Amazon EC2 FAQs

Q: What is Amazon Elastic Compute Cloud (Amazon EC2)?

Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides resizable compute capacity in the cloud. It is designed to make web-scale computing easier for developers.

Q: What can I do with Amazon EC2?

Just as Amazon Simple Storage Service (Amazon S3) enables storage in the cloud, Amazon EC2 enables “compute” in the cloud. Amazon EC2’s simple web service interface allows you to obtain and configure capacity with minimal friction. It provides you with complete control of your computing resources and lets you run on Amazon’s proven computing environment. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change. Amazon EC2 changes the economics of computing by allowing you to pay only for capacity that you actually use.

Q: How can I get started with Amazon EC2?

To sign up for Amazon EC2, click the “Sign up for This Web Service” button on the Amazon EC2 detail page. You must have an Amazon Web Services account to access this service; if you do not already have one, you will be prompted to create one when you begin the Amazon EC2 sign-up process. After signing up, please refer to the Amazon EC2 documentation, which includes our Getting Started Guide.

Q: Why am I asked to verify my phone number when signing up for Amazon EC2?

Amazon EC2 registration requires you to have a valid phone number and email address on file with AWS in case we ever need to contact you. Verifying your phone number takes only a couple of minutes and involves receiving a phone call during the registration process and entering a PIN number using the phone key pad.

Q: What can developers now do that they could not before?

Until now, small developers did not have the capital to acquire massive compute resources and ensure they had the capacity they needed to handle unexpected spikes in load. Amazon EC2 enables any developer to leverage Amazon’s own benefits of massive scale with no up-front investment or performance compromises. Developers are now free to innovate knowing that no matter how successful their businesses become, it will be inexpensive and simple to ensure they have the compute capacity they need to meet their business requirements.

The “Elastic” nature of the service allows developers to instantly scale to meet spikes in traffic or demand. When computing requirements unexpectedly change (up or down), Amazon EC2 can instantly respond, meaning that developers have the ability to control how many resources are in use at any given point in time. In contrast, traditional hosting services generally provide a fixed number of resources for a fixed amount of time, meaning that users have a limited ability to easily respond when their usage is rapidly changing, unpredictable, or is known to experience large peaks at various intervals.

Q: How do I run systems in the Amazon EC2 environment?

Once you have set up your account and select or create your AMIs, you are ready to boot your instance. You can start your AMI on any number of On-Demand instances by using the RunInstances API call. You simply need to indicate how many instances you wish to launch. If you wish to run more than 20 On-Demand instances, complete the Amazon EC2 instance request form.

If Amazon EC2 is able to fulfill your request, RunInstances will return success, and we will start launching your instances. You can check on the status of your instances using the DescribeInstances API call. You can also programmatically terminate any number of your instances using the TerminateInstances API call.

If you have a running instance using an Amazon EBS boot partition, you can also use the StopInstances API call to release the compute resources but preserve the data on the boot partition. You can use the StartInstances API when you are ready to restart the associated instance with the Amazon EBS boot partition.

In addition, you have the option to use Spot Instances to reduce your computing costs when you have flexibility in when your applications can run. Read more about Spot Instances for a more detailed explanation on how Spot Instances work.

If you prefer, you can also perform all these actions from the AWS Management Console or through the command line using our command line tools, which have been implemented with this web service API.

Q: What is the difference between using the local instance store and Amazon Elastic Block Store (Amazon EBS) for the root device?

When you launch your Amazon EC2 instances you have the ability to store your root device data on Amazon EBS or the local instance store. By using Amazon EBS, data on the root device will persist independently from the lifetime of the instance. This enables you to stop and restart the instance at a subsequent time, which is similar to shutting down your laptop and restarting it when you need it again.

Alternatively, the local instance store only persists during the life of the instance. This is an inexpensive way to launch instances where data is not stored to the root device. For example, some customers use this option to run large web sites where each instance is a clone to handle web traffic.

Q: How quickly will systems be running?

It typically takes less than 10 minutes from the issue of the RunInstances call to the point where all requested instances begin their boot sequences. This time depends on a number of factors including: the size of your AMI, the number of instances you are launching, and how recently you have launched that AMI. Images launched for the first time may take slightly longer to boot.

Q: How do I load and store my systems with Amazon EC2?

Amazon EC2 allows you to set up and configure everything about your instances from your operating system up to your applications. An Amazon Machine Image (AMI) is simply a packaged-up environment that includes all the necessary bits to set up and boot your instance. Your AMIs are your unit of deployment. You might have just one AMI or you might compose your system out of several building block AMIs (e.g., webservers, appservers, and databases). Amazon EC2 provides a number of tools to make creating an AMI easy. Once you create a custom AMI, you will need to bundle it. If you are bundling an image with a root device backed by Amazon EBS, you can simply use the bundle command in the AWS Management Console. If you are bundling an image with a boot partition on the instance store, then you will need to use the AMI Tools to upload it to Amazon S3. Amazon EC2 uses Amazon EBS and Amazon S3 to provide reliable, scalable storage of your AMIs so that we can boot them when you ask us to do so.

Or, if you want, you don’t have to set up your own AMI from scratch. You can choose from a number of globally available AMIs that provide useful instances. For example, if you just want a simple Linux server, you can choose one of the standard Linux distribution AMIs.

Q: How do I access my systems?

The RunInstances call that initiates execution of your application stack will return a set of DNS names, one for each system that is being booted. This name can be used to access the system exactly as you would if it were in your own data center. You own that machine while your operating system stack is executing on it.

Q: Is Amazon EC2 used in conjunction with Amazon S3?

Yes, Amazon EC2 is used jointly with Amazon S3 for instances with root devices backed by local instance storage. By using Amazon S3, developers have access to the same highly scalable, reliable, fast, inexpensive data storage infrastructure that Amazon uses to run its own global network of web sites. In order to execute systems in the Amazon EC2 environment, developers use the tools provided to load their AMIs into Amazon S3 and to move them between Amazon S3 and Amazon EC2. See How do I load and store my systems with Amazon EC2? for more information about AMIs.

We expect developers to find the combination of Amazon EC2 and Amazon S3 to be very useful. Amazon EC2 provides cheap, scalable compute in the cloud while Amazon S3 allows users to store their data reliably.

Q: How many instances can I run in Amazon EC2?

You are limited to running up to a total of 20 On-Demand instances across the instance family, purchasing 20 Reserved Instances, and requesting Spot Instances per your dynamic Spot limit per region. New AWS accounts may start with limits that are lower than the limits described here. Certain instance types are further limited per region as follows:

Note that cc2.8xlarge, hs1.8xlarge, cr1.8xlarge, G2, D2, and I2 instances are not available in all regions.

If you need more instances, complete the Amazon EC2 instance request form with your use case and your instance increase will be considered. Limit increases are tied to the region they were requested for.

Q: Are there any limitations in sending email from Amazon EC2 instances?

Yes. In order to maintain the quality of Amazon EC2 addresses for sending email, we enforce default limits on the amount of email that can be sent from EC2 accounts. If you wish to send larger amounts of email from EC2, you can apply to have these limits removed from your account by filling out this form.

Q: How quickly can I scale my capacity both up and down?

Amazon EC2 provides a truly elastic computing environment. Amazon EC2 enables you to increase or decrease capacity within minutes, not hours or days. You can commission one, hundreds or even thousands of server instances simultaneously. When you need more instances, you simply call RunInstances, and Amazon EC2 will typically set up your new instances in a matter of minutes. Of course, because this is all controlled with web service APIs, your application can automatically scale itself up and down depending on its needs.

Q: What operating system environments are supported?

Amazon EC2 currently supports a variety of operating systems including: Amazon Linux, Ubuntu, Windows Server, Red Hat Enterprise Linux, SUSE Linux Enterprise Server, Fedora, Debian, CentOS, Gentoo Linux, Oracle Linux, and FreeBSD. We are looking for ways to expand it to other platforms.

Q: Does Amazon EC2 use ECC memory?

In our experience, ECC memory is necessary for server infrastructure, and all the hardware underlying Amazon EC2 uses ECC memory.

Q: How is this service different than a plain hosting service?

Traditional hosting services generally provide a pre-configured resource for a fixed amount of time and at a predetermined cost. Amazon EC2 differs fundamentally in the flexibility, control and significant cost savings it offers developers, allowing them to treat Amazon EC2 as their own personal data center with the benefit of Amazon.com’s robust infrastructure.

When computing requirements unexpectedly change (up or down), Amazon EC2 can instantly respond, meaning that developers have the ability to control how many resources are in use at any given point in time. In contrast, traditional hosting services generally provide a fixed number of resources for a fixed amount of time, meaning that users have a limited ability to easily respond when their usage is rapidly changing, unpredictable, or is known to experience large peaks at various intervals.

Secondly, many hosting services don’t provide full control over the compute resources being provided. Using Amazon EC2, developers can choose not only to initiate or shut down instances at any time, they can completely customize the configuration of their instances to suit their needs – and change it at any time. Most hosting services cater more towards groups of users with similar system requirements, and so offer limited ability to change these.

Finally, with Amazon EC2 developers enjoy the benefit of paying only for their actual resource consumption – and at very low rates. Most hosting services require users to pay a fixed, up-front fee irrespective of their actual computing power used, and so users risk overbuying resources to compensate for the inability to quickly scale up resources within a short time frame.

Q: How will I be charged and billed for my use of Amazon EC2?

You pay only for what you use. Displayed pricing is an hourly rate but depending on which instances you choose, you pay by the hour or second (minimum of 60 seconds) for each instance type. Partial instance-hours consumed are billed based on instance usage. Data transferred between AWS services in different regions will be charged as Internet Data Transfer on both sides of the transfer. Usage for other Amazon Web Services is billed separately from Amazon EC2.

For EC2 pricing information, please visit the pricing section on the EC2 detail page.

Q: When does billing of my Amazon EC2 systems begin and end?

Billing commences when Amazon EC2 initiates the boot sequence of an AMI instance. Billing ends when the instance terminates, which could occur through a web services command, by running "shutdown -h", or through instance failure. When you stop an instance, we shut it down but don't charge hourly usage for a stopped instance, or data transfer fees, but we do charge for the storage for any Amazon EBS volumes. To learn more, visit the AWS Documentation.

Q: What defines billable EC2 instance usage?

Instance usages are billed for any time your instances are in a "running" state. If you no longer wish to be charged for your instance, you must "stop" or "terminate" the instance to avoid being billed for additional instance usage. Billing starts when an instance transitions into the running state.

Q: If I have two instances in different availability zones, how will I be charged for regional data transfer?

Each instance is charged for its data in and data out at corresponding Data Transfer rates. Therefore, if data is transferred between these two instances, it is charged at "Data Transfer Out from EC2 to Another AWS Region" for the first instance and at "Data Transfer In from Another AWS Region" for the second instance. Please refer to this page for detailed data transfer.

Q. If I have two instances in different regions, how will I be charged for data transfer?

Each instance is charged for its data in and data out at Internet Data Transfer rates. Therefore, if data is transferred between these two instances, it is charged at Internet Data Transfer Out for the first instance and at Internet Data Transfer In for the second instance.

Q: How will my monthly bill show per-second versus per-hour?

Although EC2 charges in your monthly bill will now be calculated based on a per second basis, for consistency, the monthly EC2 bill will show cumulative usage for each instance that ran in a given month in decimal hours. An example would be an instance running for 1 hour 10 minutes and 4 seconds would look like 1.1677. Read this blog for an example of the detailed billing report.

Q: Do your prices include taxes?

Except as otherwise noted, our prices are exclusive of applicable taxes and duties, including VAT and applicable sales tax. For customers with a Japanese billing address, use of AWS services is subject to Japanese Consumption Tax. Learn more.

Q: What kind of hardware will my application stack run on?

Visit Amazon EC2 Instance Type for a list of EC2 instances available by region.

Q: How do I select the right instance type?

Amazon EC2 instances are grouped into 5 families: General Purpose, Compute Optimized, Memory Optimized, Storage Optimized and Accelerated Computing instances. General Purpose Instances have memory to CPU ratios suitable for most general purpose applications and come with fixed performance (M5, M4) or burstable performance (T2); Compute Optimized instances (C5, C5n, C4) have proportionally more CPU resources than memory (RAM) and are well suited for scale out compute-intensive applications and High Performance Computing (HPC) workloads; Memory Optimized Instances (X1e, X1, R5, R4) offer larger memory sizes for memory-intensive applications, including database and memory caching applications; Accelerating Computing instances (P3, P2, G3, F1) take advantage of the parallel processing capabilities of NVIDIA Tesla GPUs for high performance computing and machine/deep learning; GPU Graphics instances (G3) offer high-performance 3D graphics capabilities for applications using OpenGL and DirectX; F1 instances deliver Xilinx FPGA-based reconfigurable computing; Storage Optimized Instances (H1, I3, D2) that provide very high, low latency, I/O capacity using SSD-based local instance storage for I/O-intensive applications, with D2 or H1, the dense-storage and HDD-storage instances, provide local high storage density and sequential I/O performance for data warehousing, Hadoop and other data-intensive applications. When choosing instance types, you should consider the characteristics of your application with regards to resource utilization (i.e. CPU, Memory, Storage) and select the optimal instance family and instance size.

Q: What is an “EC2 Compute Unit” and why did you introduce it?

Transitioning to a utility computing model fundamentally changes how developers have been trained to think about CPU resources. Instead of purchasing or leasing a particular processor to use for several months or years, you are renting capacity by the hour. Because Amazon EC2 is built on commodity hardware, over time there may be several different types of physical hardware underlying EC2 instances. Our goal is to provide a consistent amount of CPU capacity no matter what the actual underlying hardware.

Amazon EC2 uses a variety of measures to provide each instance with a consistent and predictable amount of CPU capacity. In order to make it easy for developers to compare CPU capacity between different instance types, we have defined an Amazon EC2 Compute Unit. The amount of CPU that is allocated to a particular instance is expressed in terms of these EC2 Compute Units. We use several benchmarks and tests to manage the consistency and predictability of the performance from an EC2 Compute Unit. The EC2 Compute Unit (ECU) provides the relative measure of the integer processing power of an Amazon EC2 instance. Over time, we may add or substitute measures that go into the definition of an EC2 Compute Unit, if we find metrics that will give you a clearer picture of compute capacity.

Q: What is the regional availability of Amazon EC2 instance types?
For a list of all instances and regional availability, visit Amazon EC2 Pricing.

Q: How do I prevent other people from viewing my systems?

You have complete control over the visibility of your systems. The Amazon EC2 security systems allow you to place your running instances into arbitrary groups of your choice. Using the web services interface, you can then specify which groups may communicate with which other groups, and also which IP subnets on the Internet may talk to which groups. This allows you to control access to your instances in our highly dynamic environment. Of course, you should also secure your instance as you would any other server.

Q: Can I get a history of all EC2 API calls made on my account for security analysis and operational troubleshooting purposes?

Yes. To receive a history of all EC2 API calls (including VPC and EBS) made on your account, you simply turn on CloudTrail in the AWS Management Console.  For more information, visit the CloudTrail home page. 

Q: Where can I find more information about security on AWS?

For more information on security on AWS please refer to our Amazon Web Services: Overview of Security Processes white paper and to our Amazon EC2 running Windows Security Guide.

Q: Why am I limited to 5 Elastic IP addresses per region?

Public (IPV4) internet addresses are a scarce resource. There is only a limited amount of public IP space available, and Amazon EC2 is committed to helping use that space efficiently.

By default, all accounts are limited to 5 Elastic IP addresses per region. If you need more the 5 Elastic IP addresses, we ask that you apply for your limit to be raised. We will ask you to think through your use case and help us understand your need for additional addresses. You can apply for more Elastic IP address here. Any increases will be specific to the region they have been requested for.

Q: Why am I charged when my Elastic IP address is not associated with a running instance?

In order to help ensure our customers are efficiently using the Elastic IP addresses, we impose a small hourly charge for each address when it is not associated to a running instance.

Q: Do I need one Elastic IP address for every instance that I have running?

No. You do not need an Elastic IP address for all your instances. By default, every instance comes with a private IP address and an internet routable public IP address. The private IP address remains associated with the network interface when the instance is stopped and restarted, and is released when the instance is terminated. The public address is associated exclusively with the instance until it is stopped, terminated or replaced with an Elastic IP address. These IP addresses should be adequate for many applications where you do not need a long lived internet routable end point. Compute clusters, web crawling, and backend services are all examples of applications that typically do not require Elastic IP addresses.

Q: How long does it take to remap an Elastic IP address?

The remap process currently takes several minutes from when you instruct us to remap the Elastic IP until it fully propagates through our system.

Q: Can I configure the reverse DNS record for my Elastic IP address?

Yes, you can configure the reverse DNS record of your Elastic IP address by filling out this form. Note that a corresponding forward DNS record pointing to that Elastic IP address must exist before we can create the reverse DNS record.

Q: How isolated are Availability Zones from one another?

Each Availability Zone runs on its own physically distinct, independent infrastructure, and is engineered to be highly reliable. Common points of failures like generators and cooling equipment are not shared across Availability Zones. Additionally, they are physically separate, such that even extremely uncommon disasters such as fires, tornados or flooding would only affect a single Availability Zone.

Q: Is Amazon EC2 running in more than one region?

Yes. Please refer to Regional Products and Services for more details of our product and service availability by region.

Q: How can I make sure that I am in the same Availability Zone as another developer?

We do not currently support the ability to coordinate launches into the same Availability Zone across AWS developer accounts. One Availability Zone name (for example, us-east-1a) in two AWS customer accounts may relate to different physical Availability Zones.

Q: If I transfer data between Availability Zones using public IP addresses, will I be charged twice for Regional Data Transfer (once because it’s across zones, and a second time because I’m using public IP addresses)?

No. Regional Data Transfer rates apply if at least one of the following is true, but is only charged once for a given instance even if both are true:

• The other instance is in a different Availability Zone, regardless of which type of address is used.
• Public or Elastic IP addresses are used, regardless of which Availability Zone the other instance is in.
  

Q. What is the Nitro Hypervisor?

The launch of C5 instances introduced a new hypervisor for Amazon EC2, the Nitro Hypervisor. As a component of the Nitro system, the Nitro Hypervisor primarily provides CPU and memory isolation for EC2 instances. VPC networking and EBS storage resources are implemented by dedicated hardware components, Nitro Cards that are part of all current generation EC2 instance families. The Nitro Hypervisor is built on core Linux Kernel-based Virtual Machine (KVM) technology, but does not include general-purpose operating system components.

Q. How does the Nitro Hypervisor benefit customers?

The Nitro Hypervisor provides consistent performance and increased compute and memory resources for EC2 virtualized instances by removing host system software components. It allows AWS to offer larger instance sizes (like c5.18xlarge) that provide practically all of the resources from the server to customers. Previously, C3 and C4 instances each eliminated software components by moving VPC and EBS functionality to hardware designed and built by AWS. This hardware enables the Nitro Hypervisor to be very small and uninvolved in data processing tasks for networking and storage.

Q. Will all EC2 instances use the Nitro Hypervisor?

Eventually all new instance types will use the Nitro Hypervisor, but in the near term, some new instance types will use Xen depending on the requirements of the platform.

Q. Will AWS continue to invest in its Xen-based hypervisor?

Yes. As AWS expands its global cloud infrastructure, EC2’s use of its Xen-based hypervisor will also continue to grow. Xen will remain a core component of EC2 instances for the foreseeable future. AWS is a founding member of the Xen Project since its establishment as a Linux Foundation Collaborative Project and remains an active participant on its Advisory Board. As AWS expands its global cloud infrastructure, EC2’s Xen-based hypervisor also continues to grow. Therefore EC2’s investment in Xen continues to grow, not shrink

Q. How many EBS volumes and Elastic Network Interfaces (ENIs) can be attached to instances running on the Nitro Hypervisor?

Instances running on the Nitro Hypervisor support a maximum of 27 additional PCI devices for EBS volumes and VPC ENIs. Each EBS volume or VPC ENI uses a PCI device. For example, if you attach 3 additional network interfaces to an instance that uses the Nitro Hypervisor, you can attach up to 24 EBS volumes to that instance.

Q. Will the Nitro Hypervisor change the APIs used to interact with EC2 instances?

No, all the public facing APIs for interacting with EC2 instances that run using the Nitro Hypervisor will remain the same. For example, the “hypervisor” field of the DescribeInstances response, which will continue to report “xen” for all EC2 instances, even those running under the Nitro Hypervisor. This field may be removed in a future revision of the EC2 API.

Q. Which AMIs are supported on instances that use the Nitro Hypervisor?

EBS backed HVM AMIs with support for ENA networking and booting from NVMe storage can be used with instances that run under the Nitro Hypervisor. The latest Amazon Linux AMI and Windows AMIs provided by Amazon are supported, as are the latest AMI of Ubuntu, Debian, Red Hat Enterprise Linux, SUSE Enterprise Linux, CentOS, and FreeBSD.

Q. Will I notice any difference between instances using Xen hypervisor and those using the Nitro Hypervisor?

Yes. For example, instances running under the Nitro Hypervisor boot from EBS volumes using an NVMe interface. Instances running under Xen boot from an emulated IDE hard drive, and switch to the Xen paravirtualized block device drivers.

Operating systems can identify when they are running under a hypervisor. Some software assumes that EC2 instances will run under the Xen hypervisor and rely on this detection. Operating systems will detect they are running under KVM when an instance uses the Nitro Hypervisor, so the process to identify EC2 instances should be used to identify EC2 instances that run under both hypervisors.

All the features of EC2 such as Instance Metadata Service work the same way on instances running under both Xen and the Nitro Hypervisor. The majority of applications will function the same way under both Xen and the Nitro Hypervisor as long as the operating system has the needed support for ENA networking and NVMe storage.

Q. How are instance reboot and termination EC2 API requests implemented by the Nitro Hypervisor?

The Nitro Hypervisor signals the operating system running in the instance that it should shut down cleanly by industry standard ACPI methods. For Linux instances, this requires that acpid be installed and functioning correctly. If acpid is not functioning in the instance, termination events will be delayed by multiple minutes and will then execute as a hard reset or power off.

Q. How do EBS volumes behave when accessed by NVMe interfaces?

There are some important differences in how operating system NVMe drivers behave compared to Xen paravirtual (PV) block drivers.

First, the NVMe device names used by Linux based operating systems will be different than the parameters for EBS volume attachment requests and block device mapping entries such as /dev/xvda and /dev/xvdf. NVMe devices are enumerated by the operating system as /dev/nvme0n1, /dev/nvme1n1, and so on. The NVMe device names are not persistent mappings to volumes, therefore other methods like file system UUIDs or labels should be used when configuring the automatic mounting of file systems or other startup activities. When EBS volumes are accessed via the NVMe interface, the EBS volume ID is available via the controller serial number and the device name specified in EC2 API requests is provided by an NVMe vendor extension to the Identify Controller command. This enables backward compatible symbolic links to be created by a utility script. For more information see the EC2 documentation on device naming and NVMe based EBS volumes.

Second, by default the NVMe drivers included in most operating systems implement an I/O timeout. If an I/O does not complete in an implementation specific amount of time, usually tens of seconds, the driver will attempt to cancel the I/O, retry it, or return an error to the component that issued the I/O. The Xen PV block device interface does not time out I/O, which can result in processes that cannot be terminated if it is waiting for I/O. The Linux NVMe driver behavior can be modified by specifying a higher value for the nvme.io timeout kernel module parameter.

Third, the NVMe interface can transfer much larger amounts of data per I/O, and in some cases may be able to support more outstanding I/O requests, compared to the Xen PV block interface. This can cause higher I/O latency if very large I/Os or a large number of I/O requests are issued to volumes designed to support throughput workloads like EBS Throughput Optimized HDD (st1) and Cold HDD (sc1) volumes. This I/O latency is normal for throughput optimized volumes in these scenarios, but may cause I/O timeouts in NVMe drivers. The I/O timeout can be adjusted in the Linux driver by specifying a larger value for the nvme_core.io_timeout kernel module parameter.

Q: What networking capabilities are included in this feature?

We currently support enhanced networking capabilities using SR-IOV (Single Root I/O Virtualization). SR-IOV is a method of device virtualization that provides higher I/O performance and lower CPU utilization compared to traditional implementations. For supported Amazon EC2 instances, this feature provides higher packet per second (PPS) performance, lower inter-instance latencies, and very low network jitter.

Q: Why should I use Enhanced Networking?

If your applications benefit from high packet-per-second performance and/or low latency networking, Enhanced Networking will provide significantly improved performance, consistence of performance and scalability.

Q: How can I enable Enhanced Networking on supported instances?

In order to enable this feature, you must launch an HVM AMI with the appropriate drivers. C5, C5n, C5d, F1, G3, H1, I3, m4.16xlarge, M5, M5a, M5d, P2, P3, R4, R5, R5a, R5d, T3, X1, X1e, and z1d instances use the Elastic Network Adapter (which uses the “ena” Linux driver) for Enhanced Networking. C3, C4, D2, I2, M4 (excluding m4.16xlarge), and R3 instances use Intel® 82599g Virtual Function Interface (which uses the “ixgbevf” Linux driver). Amazon Linux AMI includes both of these drivers by default. For AMIs that do not contain these drivers, you will need to download and install the appropriate drivers based on the instance types you plan to use. You can use Linux or Windows instructions to enable Enhanced Networking in AMIs that do not include the SR-IOV driver by default. Enhanced Networking is only supported in Amazon VPC.

Q: Do I need to pay an additional fee to use Enhanced Networking?

No, there is no additional fee for Enhanced Networking. To take advantage of Enhanced Networking you need to launch the appropriate AMI on a supported instance type in a VPC.

Q: Why is Enhanced Networking only supported in Amazon VPC?

Amazon VPC allows us to deliver many advanced networking features to you that are not possible in EC2-Classic. Enhanced Networking is another example of a capability enabled by Amazon VPC.

Q: Which instance types support Enhanced Networking?

Depending on your instance type, enhanced networking can be enabled using one of the following mechanisms:

Intel 82599 Virtual Function (VF) interface - The Intel 82599 Virtual Function interface supports network speeds of up to 10 Gbps for supported instance types. C3, C4, D2, I2, M4 (excluding m4.16xlarge), and R3 instances use the Intel 82599 VF interface for enhanced networking.

Elastic Network Adapter (ENA) - The Elastic Network Adapter (ENA) supports network speeds of up to 100 Gbps for supported instance types. C5, C5n, C5d, F1, G3, H1, I3, m4.16xlarge, M5, M5a, M5d, P2, P3, R4, R5, R5a, R5d, T3, X1, X1e, and z1d instances use the Elastic Network Adapter for enhanced networking.

Q. Which instance types offer NVMe instance storage?

High I/O instances use NVMe based local instance storage to deliver very high, low latency, I/O capacity to applications, and are optimized for applications that require millions of IOPS. Like Cluster instances, High I/O instances can be clustered via cluster placement groups for high bandwidth networking.

Q: Why should I use EFA?

EFA brings the scalability, flexibility, and elasticity of cloud to tightly-coupled HPC applications. With EFA, tightly-coupled HPC applications have access to lower and more consistent latency and higher throughput than traditional TCP channels, enabling them to scale better. EFA support can be enabled dynamically, on-demand on any supported EC2 instance without pre-reservation, giving you the flexibility to respond to changing business/workload priorities.

Q: What types of applications can benefit from using EFA?

High Performance Computing (HPC) applications distribute computational workloads across a cluster of instances for parallel processing. Examples of HPC applications include computational fluid dynamics (CFD), crash simulations, and weather simulations. HPC applications are generally written using the Message Passing Interface (MPI) and impose stringent requirements for inter-instance communication in terms of both latency and bandwidth. Applications using MPI and other HPC middleware which supports the libfabric communication stack can benefit from EFA.

Q: How does EFA communication work?

EFA devices provide all ENA devices functionalities plus a new OS bypass hardware interface that allows user-space applications to communicate directly with the hardware-provided reliable transport functionality. Most applications will use existing middleware, such as the Message Passing Interface (MPI), to interface with EFA. AWS has worked with a number of middleware providers to ensure support for the OS bypass functionality of EFA. Please note that communication using the OS bypass functionality is limited to instances within a single subnet of a Virtual Private Cloud (VPC).

Q: Which instance types support EFA?

EFA is currently available on the C5n.18xlarge, C5n.9xlarge, and P3dn.24xl instance sizes. Support for more instance types and sizes being added in the coming months.

Q: What are the differences between an EFA ENI and an ENA ENI?

An ENA ENI provides traditional IP networking features necessary to support VPC networking. An EFA ENI provides all the functionality of an ENA ENI, plus hardware support for applications to communicate directly with the EFA ENI without involving the instance kernel (OS-bypass communication) using an extended programming interface. Due to the advanced capabilities of the EFA ENI, EFA ENIs can only be attached at launch or to stopped instances.

Q: What are the pre-requisites to enabling EFA on an instance?

EFA support can be enabled either at the launch of the instance or added to a stopped instance. EFA devices cannot be attached to a running instance.  

Q: Can I use EFA today?

EFA is currently in preview mode. Please sign up to request access to try EFA capabilities to enhance your HPC workloads. The EFA team will reach out to you with the details needed to get started.

Q: What happens to my data when a system terminates?

The data stored on a local instance store will persist only as long as that instance is alive. However, data that is stored on an Amazon EBS volume will persist independently of the life of the instance. Therefore, we recommend that you use the local instance store for temporary data and, for data requiring a higher level of durability, we recommend using Amazon EBS volumes or backing up the data to Amazon S3. If you are using an Amazon EBS volume as a root partition, you will need to set the Delete On Terminate flag to "N" if you want your Amazon EBS volume to persist outside the life of the instance.

Q: What kind of performance can I expect from Amazon EBS volumes?

Amazon EBS provides four current generation volume types and are divided into two major categories: SSD-backed storage for transactional workloads and HDD-backed storage for throughput intensive workloads. These volume types differ in performance characteristics and price, allowing you to tailor your storage performance and cost to the needs of your applications. For more information on see the EBS product details page, and for additional information on performance, see the Amazon EC2 User Guide's EBS Performance section.

Q: What are Throughput Optimized HDD (st1) and Cold HDD (sc1) volume types?

ST1 volumes are backed by hard disk drives (HDDs) and are ideal for frequently accessed, throughput intensive workloads with large datasets and large I/O sizes, such as MapReduce, Kafka, log processing, data warehouse, and ETL workloads. These volumes deliver performance in terms of throughput, measured in MB/s, and include the ability to burst up to 250 MB/s per TB, with a baseline throughput of 40 MB/s per TB and a maximum throughput of 500 MB/s per volume. ST1 is designed to deliver the expected throughput performance 99% of the time and has enough I/O credits to support a full-volume scan at the burst rate.

SC1 volumes are backed by hard disk drives (HDDs) and provides the lowest cost per GB of all EBS volume types. It is ideal for less frequently accessed workloads with large, cold datasets. Similar to st1, sc1 provides a burst model: these volumes can burst up to 80 MB/s per TB, with a baseline throughput of 12 MB/s per TB and a maximum throughput of 250 MB/s per volume. For infrequently accessed data, sc1 provides extremely inexpensive storage. SC1 is designed to deliver the expected throughput performance 99% of the time and has enough I/O credits to support a full-volume scan at the burst rate.

To maximize the performance of st1 and sc1, we recommend using EBS-optimized EC2 instances.

Q: Which volume type should I choose?

Amazon EBS includes two major categories of storage: SSD-backed storage for transactional workloads (performance depends primarily on IOPS) and HDD-backed storage for throughput workloads (performance depends primarily on throughput, measured in MB/s). SSD-backed volumes are designed for transactional, IOPS-intensive database workloads, boot volumes, and workloads that require high IOPS. SSD-backed volumes include Provisioned IOPS SSD (io1) and General Purpose SSD (gp2). HDD-backed volumes are designed for throughput-intensive and big-data workloads, large I/O sizes, and sequential I/O patterns. HDD-backed volumes include Throughput Optimized HDD (st1) and Cold HDD (sc1). For more information on Amazon EBS see the EBS product details page.

Q: Do you support multiple instances accessing a single volume?

While you are able to attach multiple volumes to a single instance, attaching multiple instances to one volume is not supported at this time.

Q: Will I be able to access my EBS snapshots using the regular Amazon S3 APIs?

No, EBS snapshots are only available through the Amazon EC2 APIs.

Q: Do volumes need to be un-mounted in order to take a snapshot? Does the snapshot need to complete before the volume can be used again? 

No, snapshots can be done in real time while the volume is attached and in use. However, snapshots only capture data that has been written to your Amazon EBS volume, which might exclude any data that has been locally cached by your application or OS. In order to ensure consistent snapshots on volumes attached to an instance, we recommend cleanly detaching the volume, issuing the snapshot command, and then reattaching the volume. For Amazon EBS volumes that serve as root devices, we recommend shutting down the machine to take a clean snapshot.

Q: Are snapshots versioned? Can I read an older snapshot to do a point-in-time recovery?

Each snapshot is given a unique identifier, and customers can create volumes based on any of their existing snapshots.

Q: What charges apply when using Amazon EBS shared snapshots?

If you share a snapshot, you won’t be charged when other users make a copy of your snapshot. If you make a copy of another user’s shared volume, you will be charged normal EBS rates.

Q: Can users of my Amazon EBS shared snapshots change any of my data?

Users who have permission to create volumes based on your shared snapshots will first make a copy of the snapshot into their account. Users can modify their own copies of the data, but the data on your original snapshot and any other volumes created by other users from your original snapshot will remain unmodified.

Q: How can I discover Amazon EBS snapshots that have been shared with me?

You can find snapshots that have been shared with you by selecting “Private Snapshots” from the viewing dropdown in the Snapshots section of the AWS Management Console. This section will list both snapshots you own and snapshots that have been shared with you.

Q: How can I find what Amazon EBS snapshots are shared globally?

You can find snapshots that have been shared globally by selecting “Public Snapshots” from the viewing dropdown in the Snapshots section of the AWS Management Console.

Q: Do you offer encryption on Amazon EBS volumes and snapshots?

Yes. EBS offers seamless encryption of data volumes and snapshots. EBS encryption better enables you to meet security and encryption compliance requirements.

Q: How can I find a list of Amazon Public Data Sets?

All information on Public Data Sets is available in our Public Data Sets Resource Center. You can also obtain a listing of Public Data Sets within the AWS Management Console by choosing “Amazon Snapshots” from the viewing dropdown in the Snapshots section.

Q: Where can I learn more about EBS?

You can visit the Amazon EBS FAQ page.

Q. How do I access a file system from an Amazon EC2 instance?

To access your file system, you mount the file system on an Amazon EC2 Linux-based instance using the standard Linux mount command and the file system’s DNS name. Once you’ve mounted, you can work with the files and directories in your file system just like you would with a local file system.

Amazon EFS uses the NFSv4.1 protocol. For a step-by-step example of how to access a file system from an Amazon EC2 instance, please see the Amazon EFS Getting Started guide.

Q. What Amazon EC2 instance types and AMIs work with Amazon EFS?

Amazon EFS is compatible with all Amazon EC2 instance types and is accessible from Linux-based AMIs. You can mix and match the instance types connected to a single file system. For a step-by-step example of how to access a file system from an Amazon EC2 instance, please see the Amazon EFS Getting Started guide.

Q. How do I load data into a file system?

You can load data into an Amazon EFS file system from your Amazon EC2 instances or from your on-premises datacenter servers.

Amazon EFS file systems can be mounted on an Amazon EC2 instance, so any data that is accessible to an Amazon EC2 instance can also be read and written to Amazon EFS. To load data that is not currently stored on the Amazon cloud, you can use the same methods you use to transfer files to Amazon EC2 today, such as Secure Copy (SCP).

Amazon EFS file systems can also be mounted on an on-premises server, so any data that is accessible to an on-premises server can be read and written to Amazon EFS using standard Linux tools. For more information about accessing a file system from an on-premises server, please see the On-premises Access section of the Amazon EFS FAQ.

For more information about moving data to the Amazon cloud, please see the Cloud Data Migration page.

Q. How do I access my file system from outside my VPC?

Amazon EC2 instances within your VPC can access your file system directly, and Amazon EC2 Classic instances outside your VPC can mount a file system via ClassicLink. On-premises servers can mount your file systems via an AWS Direct Connect connection to your VPC.

Q. How many Amazon EC2 instances can connect to a file system?

Amazon EFS supports one to thousands of Amazon EC2 instances connecting to a file system concurrently.

Q: Where can I learn more about EFS?

You can visit the Amazon EFS FAQ page.

Q: What is the minimum time interval granularity for the data that Amazon CloudWatch receives and aggregates?

Metrics are received and aggregated at 1 minute intervals.

Q: Which operating systems does Amazon CloudWatch support?

Amazon CloudWatch receives and provides metrics for all Amazon EC2 instances and should work with any operating system currently supported by the Amazon EC2 service.

Q: Will I lose the metrics data if I disable monitoring for an Amazon EC2 instance?

You can retrieve metrics data for any Amazon EC2 instance up to 2 weeks from the time you started to monitor it. After 2 weeks, metrics data for an Amazon EC2 instance will not be available if monitoring was disabled for that Amazon EC2 instance. If you want to archive metrics beyond 2 weeks you can do so by calling mon-get-stats command from the command line and storing the results in Amazon S3 or Amazon SimpleDB.

Q: Can I access the metrics data for a terminated Amazon EC2 instance or a deleted Elastic Load Balancer?

Yes. Amazon CloudWatch stores metrics for terminated Amazon EC2 instances or deleted Elastic Load Balancers for 2 weeks.

Q: Does the Amazon CloudWatch monitoring charge change depending on which type of Amazon EC2 instance I monitor?

No, the Amazon CloudWatch monitoring charge does not vary by Amazon EC2 instance type.

Q: Why does the graphing of the same time window look different when I view in 5 minute and 1 minute periods?

If you view the same time window in a 5 minute period versus a 1 minute period, you may see that data points are displayed in different places on the graph. For the period you specify in your graph, Amazon CloudWatch will find all the available data points and calculates a single, aggregate point to represent the entire period. In the case of a 5 minute period, the single data point is placed at the beginning of the 5 minute time window. In the case of a 1 minute period, the single data point is placed at the 1 minute mark. We recommend using a 1 minute period for troubleshooting and other activities that require the most precise graphing of time periods.

Q: Can I automatically scale my Amazon EC2 fleets?

Yes. Amazon EC2 Auto Scaling is a fully managed service designed to launch or terminate Amazon EC2 instances automatically to help ensure you have the correct number of Amazon EC2 instances available to handle the load for your application. EC2 Auto Scaling helps you maintain application availability through fleet management for EC2 instances, which detects and replaces unhealthy instances, and by scaling your Amazon EC2 capacity up or down automatically according to conditions you define. You can use EC2 Auto Scaling to automatically increase the number of Amazon EC2 instances during demand spikes to maintain performance and decrease capacity during lulls to reduce costs. For more information see the Amazon EC2 Auto Scaling FAQ.

Q: What load balancing options does the Elastic Load Balancing service offer?

Elastic Load Balancing offers two types of load balancers that both feature high availability, automatic scaling, and robust security. These include the Classic Load Balancer that routes traffic based on either application or network level information, and the Application Load Balancer that routes traffic based on advanced application level information that includes the content of the request.

Q: When should I use the Classic Load Balancer and when should I use the Application Load Balancer?

The Classic Load Balancer is ideal for simple load balancing of traffic across multiple EC2 instances, while the Application Load Balancer is ideal for applications needing advanced routing capabilities, microservices, and container-based architectures. Please visit Elastic Load Balancing for more information.

Q: What is a Reserved Instance?

A Reserved Instance (RI) is an EC2 offering that provides you with a significant discount on EC2 usage when you commit to a one-year or three-year term.

Q: What are the differences between Standard RIs and Convertible RIs?

Standard RIs offer a significant discount on EC2 instance usage when you commit to a particular instance family. Convertible RIs offer you the option to change your instance configuration during the term, and still receive a discount on your EC2 usage. For more information on Convertible RIs, please click here.

Q: Do RIs provide a capacity reservation?

Yes, when a Standard or Convertible RI is scoped to a specific Availability Zone (AZ), instance capacity matching the exact RI configuration is reserved for your use (these are referred to as “zonal RIs”). Zonal RIs give you additional confidence in your ability to launch instances when you need them.

You can also choose to forego the capacity reservation and purchase Standard or Convertible RIs that are scoped to a region (referred to as “regional RIs”). Regional RIs automatically apply the discount to usage across Availability Zones and instance sizes in a region, making it easier for you to take advantage of the RI’s discounted rate.

Q: When should I purchase a zonal RI?

If you want to take advantage of the capacity reservation, then you should buy an RI in a specific Availability Zone.

Q: When should I purchase a regional RI?

If you do not require the capacity reservation, then you should buy a regional RI. Regional RIs provide AZ and instance size flexibility, which offers broader applicability of the RI’s discounted rate.

Q: What are Availability Zone and instance size flexibility?

Availability Zone and instance size flexibility make it easier for you to take advantage of your regional RI’s discounted rate. Availability Zone flexibility applies your RI’s discounted rate to usage in any Availability Zone in a region, while instance size flexibility applies your RI’s discounted rate to usage of any size within an instance family. Let’s say you own an m5.2xlarge Linux/Unix regional RI with default tenancy in US East (N.Virginia). Then this RI’s discounted rate can automatically apply to two m5.xlarge instances in us-east-1a or four m5.large instances in us-east-1b.

Q: What types of RIs provide instance size flexibility?

Linux/Unix regional RIs with the default tenancy provide instance size flexibility. Instance size flexibility is not available on RIs of other platforms such as Windows, Windows with SQL Standard, Windows with SQL Server Enterprise, Windows with SQL Server Web, RHEL, and SLES.

Q: Do I need to take any action to take advantage of Availability Zone and instance size flexibility?

Regional RIs do not require any action to take advantage of Availability Zone and instance size flexibility.

Q: I own zonal RIs how do I assign them to a region?

You can assign your Standard zonal RIs to a region by modifying the scope of the RI from a specific Availability Zone to a region from the EC2 management console or by using the ModifyReservedInstances API. 

Q: How do I purchase an RI?

To get started, you can purchase an RI from the EC2 Management Console or by using the AWS CLI. Simply specify the instance type, platform, tenancy, term, payment option, and region or Availability Zone.

Q: Can I purchase an RI for a running instance?

Yes, AWS will automatically apply an RI’s discounted rate to any applicable instance usage from the time of purchase. Visit the Getting Started page to learn more.

Q: Can I control which instances are billed at the discounted rate?

No. AWS automatically optimizes which instances are charged at the discounted rate to ensure you always pay the lowest amount. For information about billing, and how it applies to RIs, see Billing Benefits and Payment Options.

Q: How does instance size flexibility work?

EC2 uses the scale shown below, to compare different sizes within an instance family. In the case of instance size flexibility on RIs, this scale is used to apply the discounted rate of RIs to the normalized usage of the instance family. For example, if you have an m5.2xlarge RI that is scoped to a region, then your discounted rate could apply towards the usage of 1 m5.2xlarge or 2 m5.xlarge instances.

Click here to learn more about how instance size flexibility of RIs applies to your EC2 usage. And click here to learn about how instance size flexibility of RIs is presented in the Cost and Usage Report.

Q: Can I change my RI during its term?

Yes, you can modify the Availability Zone of the RI, change the scope of the RI from Availability Zone to region (and vice-versa), change the network platform from EC2-VPC to EC2-Classic (and vice versa) or modify instance sizes within the same instance family (on the Linux/Unix platform).

Q: Can I change the instance type of my RI during its term?

Yes, Convertible RIs offer you the option to change the instance type, operating system, tenancy or payment option of your RI during its term. Please refer to the Convertible RI section of the FAQ for additional information.

Q: What are the different payment options for RIs?

You can choose from three payment options when you purchase an RI. With the All Upfront option, you pay for the entire RI term with one upfront payment. With the Partial Upfront option, you make a low upfront payment and are then charged a discounted hourly rate for the instance for the duration of the RI term. The No Upfront option does not require any upfront payment and provides a discounted hourly rate for the duration of the term.

Q: When are RIs activated?

The billing discount and capacity reservation (if applicable) is activated once your payment has successfully been authorized. You can view the status (pending | active | retired) of your RIs on the "Reserved Instances" page of the Amazon EC2 Console.

Q: Do RIs apply to Spot instances or instances running on a Dedicated Host?

No, RIs do not apply to Spot instances or instances running on Dedicated Hosts. To lower the cost of using Dedicated Hosts, purchase Dedicated Host Reservations.

Q: How do RIs work with Consolidated Billing?

Our system automatically optimizes which instances are charged at the discounted rate to ensure that the consolidated accounts always pay the lowest amount. If you own RIs that apply to an Availability Zone, then only the account which owns the RI will receive the capacity reservation. However, the discount will automatically apply to usage in any account across your consolidated billing family.

Q: Can I get a discount on RI purchases?

Yes, EC2 provides tiered discounts on RI purchases. These discounts are determined based on the total list value (non-discounted price) for the active RIs you have per region. Your total list value is the sum of all expected payments for an RI within the term, including both the upfront and recurring hourly payments. The tier ranges and corresponding discounts are shown alongside.

Q: Can you help me understand how volume discounts are applied to my RI purchases?

Sure. Let's assume that you currently have $400,000 worth of active RIs in the US-east-1 region. Now, if you purchase RIs worth $150,000 in the same region, then the first $100,000 of this purchase would not receive a discount. However, the remaining $50,000 of this purchase would be discounted by 5 percent, so you would only be charged $47,500 for this portion of the purchase over the term based on your payment option.

To learn more, please visit the Understanding Reserved Instance Discount Pricing Tier portion of the Amazon EC2 User Guide.

Q: How do I calculate the list value of an RI?

Here is a sample list value calculation for three-year Partial Upfront Reserved Instances:

Q: How are volume discounts calculated if I use Consolidated Billing?

If you leverage Consolidated Billing, AWS will use the aggregate total list price of active RIs across all of your consolidated accounts to determine which volume discount tier to apply. Volume discount tiers are determined at the time of purchase, so you should activate Consolidated Billing prior to purchasing RIs to ensure that you benefit from the largest possible volume discount that your consolidated accounts are eligible to receive.

Q: Do Convertible RIs qualify for Volume Discounts?

No, however the value of each Convertible RI that you purchase contributes to your volume discount tier standing.

Q: How do I determine which volume discount tier applies to me?

To determine your current volume discount tier, please consult the Understanding Reserved Instance Discount Pricing Tiers portion of the Amazon EC2 User Guide.

Q: Will the cost of my RIs change, if my future volume qualifies me for other discount tiers?

No. Volume discounts are determined at the time of purchase, therefore the cost of your RIs will continue to remain the same as you qualify for other discount tiers. Any new purchase will be discounted according to your eligible volume discount tier at the time of purchase.

Q: Do I need to take any action at the time of purchase to receive volume discounts?

No, you will automatically receive volume discounts when you use the existing PurchaseReservedInstance API or EC2 Management Console interface to purchase RIs. If you purchase more than $10M worth of RIs contact us about receiving discounts beyond those that are automatically provided.

Q: What is a Convertible RI?
A Convertible RI is a type of Reserved Instance with attributes that can be changed during the term.

Q: When should I purchase a Convertible RI instead of a Standard RI?
The Convertible RI is useful for customers who can commit to using EC2 instances for a three-year term in exchange for a significant discount on their EC2 usage, are uncertain about their instance needs in the future, or want to benefit from changes in price.

Q: What term length options are available on Convertible RIs?
Like Standard RIs, Convertible RIs are available for purchase for a one-year or three-year term.  

Q: Can I exchange my Convertible RI to benefit from a Convertible RI matching a different instance type, operating system, tenancy, or payment option?
Yes, you can select a new instance type, operating system, tenancy, or payment option when you exchange your Convertible RIs. You also have the flexibility to exchange a portion of your Convertible RI or merge the value of multiple Convertible RIs in a single exchange. Click here to learn more about exchanging Convertible RIs.

Q: Can I transfer a Convertible or Standard RI from one region to another?
No, a RI is associated with a specific region, which is fixed for the duration of the reservation's term.

Q: How do I change the configuration of a Convertible RI?
You can change the configuration of your Convertible RI using the EC2 Management Console or the GetReservedInstancesExchangeQuote API. You also have the flexibility to exchange a portion of your Convertible RI or merge the value of multiple Convertible RIs in a single exchange. Click here to learn more about exchanging Convertible RIs.

Q: Do I need to pay a fee when I exchange my Convertible RIs?
No, you do not pay a fee when you exchange your RIs. However may need to pay a one-time true-up charge that accounts for differences in pricing between the Convertible RIs that you have and the Convertible RIs that you want.

Q: How do Convertible RI exchanges work?
When you exchange one Convertible RI for another, EC2 ensures that the total value of the Convertible RIs is maintained through a conversion. So, if you are converting your RI with a total value of $1000 for another RI, you will receive a quantity of Convertible RIs with a value that’s equal to or greater than $1000. You cannot convert your Convertible RI for Convertible RI(s) of a lesser total value.

Q: Can you define total value?
The total value is the sum of all expected payments that you’d make during the term for the RI.

Q: Can you walk me through how the true-up cost is calculated for a conversion between two All Upfront Convertible RIs?
Sure, let’s say you purchased an All Upfront Convertible RI for $1000 upfront, and halfway through the term you decide to change the attributes of the RI. Since you’re halfway through the RI term, you have $500 left of prorated value remaining on the RI. The All Upfront Convertible RI that you want to convert into costs $1,200 upfront today. Since you only have half of the term left on your existing Convertible RI, there is $600 of value remaining on the desired new Convertible RI. The true-up charge that you’ll pay will be the difference in upfront value between original and desired Convertible RIs, or $100 ($600 - $500).

Q: Can you walk me through a conversion between No Upfront Convertible RIs?
Unlike conversions between Convertible RIs with an upfront value, since you’re converting between RIs without an upfront cost, there will not be a true-up charge. However, the amount you pay on an hourly basis before the exchange will need to be greater than or equal to the amount you pay on a total hourly basis after the exchange.

For example, let’s say you purchased one No Upfront Convertible RI (A) with a $0.10/hr rate, and you decide to exchange Convertible RI A for another RI (B) that costs $0.06/hr. When you convert, you will receive two RIs of B because the amount that you pay on an hourly basis must be greater than or equal to the amount you’re paying for A on an hourly basis.

Q: Can I customize the number of instances that I receive as a result of a Convertible RI exchange?
No, EC2 uses the value of the Convertible RIs you’re trading in to calculate the minimal number of Convertible RIs you’ll receive while ensuring the result of the exchange gives you Convertible RIs of equal or greater value.

Q: Are there exchange limits for Convertible RIs?
No, there are no exchange limits for Convertible RIs.

Q: Do I have the freedom to choose any instance type when I exchange my Convertible RIs?
No, you can only exchange into Convertible RIs that are currently offered by AWS.

Q: Can I upgrade the payment option associated with my Convertible RI?
Yes, you can upgrade the payment option associated with your RI. For example, you can exchange your No Upfront RIs for Partial or All Upfront RIs to benefit from better pricing. You cannot change the payment option from All Upfront to No Upfront, and cannot change from Partial Upfront to No Upfront.

Q: Do Convertible RIs allow me to benefit from price reductions when they happen?
Yes, you can exchange your RIs to benefit from lower pricing. For example, if the price of new Convertible RIs reduces by 10%, you can exchange your Convertible RIs and benefit from the 10% reduction in price.  

Q. What is the Reserved Instance Marketplace?

The Reserved Instance Marketplace is an online marketplace that provides AWS customers the flexibility to sell their Amazon Elastic Compute Cloud (Amazon EC2) Reserved Instances to other businesses and organizations. Customers can also browse the Reserved Instance Marketplace to find an even wider selection of Reserved Instance term lengths and pricing options sold by other AWS customers.

Q. When can I list a Reserved Instance on the Reserved Instance Marketplace?

You can list a Reserved Instance when:

• You've registered as a seller in the Reserved Instance Marketplace.
• You've paid for your Reserved Instance.
• You've owned the Reserved Instance for longer than 30 days.

Q. How will I register as a seller for the Reserved Instance Marketplace?

To register for the Reserved Instance Marketplace, you can enter the registration workflow by selling a Reserved Instance from the EC2 Management Console or setting up your profile from the "Account Settings" page on the AWS portal. No matter the route, you will need to complete the following steps:

1. Start by reviewing the overview of the registration process.
2. Log in to your AWS Account.
3. Enter in the bank account into which you want us to disburse funds. Once you select "Continue", we will set that bank account as the default disbursement option.
4. In the confirmation screen, choose "Continue to Console to Start Listing".

If you exceed $20,000 in sales of Reserved Instances, or plan to sell 50 or more Reserved Instances, you will need to provide tax information before you can list your Reserved Instances. Choose "Continue with Tax Interview". During the tax interview pipeline, you will be prompted to enter your company name, contact name, address, and Tax Identification Number using the TIMS workflow. 

Additionally, if you plan to sell Reserved Instances worth more than $50,000 per year you will also need to file a limit increase.

Q. How will I know when I can start selling on the Reserved Instance Marketplace?

You can start selling on the Reserved Instance Marketplace after you have added a bank account through the registration pipeline. Once activation is complete, you will receive a confirmation email. However, it is important to note that you will not be able to receive disbursements until we are able to receive verification from your bank, which may take up to two weeks, depending on the bank you use.

Q. How do I list a Reserved Instance for sale?

To list a Reserved Instance, simply complete these steps in the Amazon EC2 Console:

1. Select the Reserved Instances you wish to sell, and choose "Sell Reserved Instances". If you have not completed the registration process, you will be prompted to register using the registration pipeline.
2. For each Reserved Instance type, set the number of instances you’d like to sell, and the price for the one-time fee you would like to set. Note that you can set the one-time price to different amounts depending on the amount of time remaining so that you don’t have to keep adjusting your one-time price if your Reserved Instance doesn’t sell quickly. By default you just need to set the current price and we will automatically decrease the one-time price by the same increment each month.
3. Once you have configured your listing, a final confirmation screen will appear. Choose "Sell Reserved Instance".

Q. Which Reserved Instances can I list for sale?

You can list any Reserved Instances that have been active for at least 30 days, and for which we have received payment. Typically, this means that you can list your reservations once they are in the active state. It is important to note that if you are an invoice customer, your Reserved Instance can be in the active state prior to AWS receiving payment. In this case, your Reserved Instance will not be listed until we have received your payment.

Q. How are listed Reserved Instances displayed to buyers?

Reserved Instances (both third-party and those offered by AWS) that have been listed on the Reserved Instance Marketplace can be viewed in the "Reserved Instances" section of the Amazon EC2 Console. You can also use the DescribeReservedInstancesListings API call.

The listed Reserved Instances are grouped based on the type, term remaining, upfront price, and hourly price. This makes it easier for buyers to find the right Reserved Instances to purchase.

Q. How much of my Reserved Instance term can I list?

You can sell a Reserved Instance for the term remaining, rounded down to the nearest month. For example, if you had 9 months and 13 days remaining, you will list it for sale as a 9-month-term Reserved Instance.

Q. Can I remove my Reserved Instance after I’ve listed it for sale?

Yes, you can remove your Reserved Instance listings at any point until a sale is pending (meaning a buyer has bought your Reserved Instance and confirmation of payment is pending).

Q. Which pricing dimensions can I set for the Reserved Instances I want to list?

Using the Reserved Instance Marketplace, you can set an upfront price you’d be willing to accept. You cannot set the hourly price (which will remain the same as was set on the original Reserved Instance), and you will not receive any funds collected from payments associated with the hourly prices.

Q. Can I still use my reservation while it is listed on the Reserved Instance Marketplace?

Yes, you will continue to receive the capacity and billing benefit of your reservation until it is sold. Once sold, any running instance that was being charged at the discounted rate will be charged at the On-Demand rate until and unless you purchase a new reservation, or terminate the instance.

Q. Can I resell a Reserved Instance that I purchased from the Reserved Instance Marketplace?

Yes, you can resell Reserved Instances purchased from the Reserved Instance Marketplace just like any other Reserved Instance.

Q. Are there any restrictions when selling Reserved Instances?

Yes, you must have a US bank account to sell Reserved Instances in the Reserved Instance Marketplace. Support for non-US bank accounts will be coming soon. Also, you may not sell Reserved Instances in the US GovCloud region.

Q. Can I sell Reserved Instances purchased from the public volume pricing tiers?

No, this capability is not yet available.

Q. Is there a charge for selling Reserved Instances on the Reserved Instance Marketplace?

Yes, AWS charges a service fee of 12% of the total upfront price of each Reserved Instance you sell in the Reserved Instance Marketplace.

Q. Can AWS sell subsets of my listed Reserved Instances?

Yes, AWS may potentially sell a subset of the quantity of Reserved Instances that you have listed. For example, if you list 100 Reserved instances, we may only have a buyer interested in purchasing 50 of them. We will sell those 50 instances and continue to list your remaining 50 Reserved Instances until and unless you decide not to list them any longer.

Q. How do buyers pay for Reserved Instances that they've purchased?

Payment for completed Reserved Instance sales are done via ACH wire transfers to a US bank account.

Q. When will I receive my money?

Once AWS has received funds from the customer that has bought your reservation, we will disburse funds via wire transfer to the bank account you specified when you registered for the Reserved Instance Marketplace.

Then, we will send you an email notification letting you know that we’ve wired you the funds. Typically, funds will appear in your account within 3-5 days of when your Reserved Instance was been sold.

Q. If I sell my Reserved Instance in the Reserved Instance Marketplace, will I get refunded for the Premium Support I was charged too?

No, you will not receive a pro-rated refund for the upfront portion of the AWS Premium Support Fee.

Q. Will I be notified about Reserved Instance Marketplace activities?

Yes, you will receive a single email once a day that details your Reserved Instance Marketplace activity whenever you create or cancel Reserved Instance listings, buyers purchase your listings, or AWS disburses funds to your bank account.

Q. What information is exchanged between the buyer and seller to help with the transaction tax calculation?

The buyer’s city, state, zip+4, and country information will be provided to the seller via a disbursement report. This information will enable sellers to calculate any necessary transaction taxes they need to remit to the government (e.g., sales tax, value-added tax, etc.). The legal entity name of the seller will also be provided on the purchase invoice.

Q. Are there any restrictions on the customers when purchasing third-party Reserved Instances?

Yes, you cannot purchase your own listed Reserved Instances, including those in any of your linked accounts (via Consolidated Billing).

Q. Do I have to pay for Premium Support when purchasing Reserved Instances from the Reserved Instance Marketplace?

Yes, if you are a Premium Support customer, you will be charged for Premium Support when you purchase a Reserved Instance through the Reserved Instance Marketplace.

Q. What is an On-Demand Capacity Reservation?

An On-Demand Capacity Reservation is an EC2 offering that lets you create and manage reserved capacity on Amazon EC2. You can create a Capacity Reservation by simply choosing an Availability Zone and quantity (number of instances) along with other instance specifications such as instance type and tenancy. Once created, the EC2 capacity is held for you regardless of whether you run instances or not. You’ll effectively pay for the full value of the reservation as long as the Capacity Reservation remains active.

Q. What is the difference between an On-Demand Capacity Reservation and a Zonal RI (RI in a specific Availability Zone), which also provides a capacity reservation?

Zonal RIs provide the benefit of capacity reservation and a discount, in return for a one to three year commitment. On-Demand Capacity Reservations allow you to reserve capacity for any duration without a commitment. With a Capacity Reservation, you can add or subtract capacity as needed, view utilization in real time, and target a reservation for a specific workload.

Q. When should I use On-Demand Capacity Reservations and when should I use RIs?

Use Capacity Reservations when you want to manage capacity independently of your RIs (discounts). For example, you can have operational teams focus on day to day capacity management through Capacity Reservations, and have a separate review process to purchase RIs with long term commitments.

Use Zonal RIs (RIs with Availability Zone specified) when you want the benefit of a capacity reservation and a discount, in return for a one to three year commitment. In this case the capacity reservation is coupled with the discount.

Use Regional RIs to automatically apply the RI’s discount to instance usage across AZs and instance sizes in a region, making it easier for you to take advantage of the RI’s discounted rate. Regional RIs don’t provide capacity reservation but their discount applies to unused On-Demand Capacity Reservations in the region with matching instance attributes.

Q. How much do Capacity Reservations cost?

When the Capacity Reservation is active, you will pay equivalent instance charges whether you run the instances or not. If you do not use the reservation, this will show up as unused reservation on your EC2 bill. When you run an instance that matches the attributes of a reservation, you just pay for the instance and nothing for the reservation. There are no upfront or additional charges.

For example, if you create a Capacity Reservation for 20 c5.2xlarge instances and you run 15 c5.2xlarge instances, you will be charged for 15 instances and 5 unused spots in the reservation (effectively charged for 20 instances).

Q. Do Regional RI discounts apply to On-Demand Capacity Reservations?

Yes. Regional RI discounts apply to unused Capacity Reservations. AWS Billing automatically applies your RI discount when the attributes of a Capacity Reservation match the attributes of an active Regional RI. When a Capacity Reservation is used by an instance, you are only charged for instance usage (with existing discounts applied) and not charged for the reservation. Regional RI discounts are preferentially applied to running instances before covering unused Capacity Reservations.

For example, if you have a Regional RI for 50 c5.2xlarge instances and a Capacity Reservation for 50 c5.2xlarge instances in the same region, the RI discount will apply to the unused portion of the reservation. Note that discounts will first apply to any c5 instance usage (across instances sizes and Availability Zones) within that region before applying to unused reservations.

Q. Do Zonal RI discounts apply to Capacity Reservations?

No. Zonal RI discounts do not apply to Capacity Reservations as Zonal RIs already provide a capacity benefit.

Q. Do I need to convert my existing Zonal RIs into a Capacity Reservation?

No. You can continue using Zonal RIs if you don't want the flexibility of a Capacity Reservation. Capacity Reservations can be paired with a Regional RI to achieve the same discount as a Zonal RI but with added benefits that come with a Capacity Reservation i.e. the ability to add or subtract capacity at any time, view utilization in real-time, and the ability to target a reservation for specific workloads.

Q. How many instances am I allowed to reserve?

The number of instances you are allowed to reserve is based on your account's On-Demand instance limit. You can reserve as many instances as that limit allows, minus the number of instances that are already running.

If you need a higher limit, contact your AWS sales representative or complete the Amazon EC2 instance request form with your use case and your instance increase will be considered. Limit increases are tied to the region they are requested for.

Q. Can I modify a Capacity Reservation after it has started?

Yes. You can reduce the number of instances you reserved at any time. You can also increase the number of instances (subject to availability). You can also modify the end time of your reservation. You cannot modify a Capacity Reservation that has ended or has been deleted.

Q. Can I end a Capacity Reservation after it has started?

Yes. You can end a Capacity Reservation by canceling it using the console or API/SDK, or by modifying your reservation to specify an end time that makes it expire automatically. Running instances are unaffected by changes to your Capacity Reservation including deletion or expiration of a reservation.

Q. Where can I find more information about using Capacity Reservations?

Refer to Linux or windows  technical documentation to learn about creating and using a Capacity Reservation.

Q. What is Amazon EC2 Fleet?

With a single API call, EC2 Fleet lets you provision compute capacity across different instance types, Availability Zones and across On-Demand, Reserved Instances (RI) and Spot Instances purchase models to help optimize scale, performance and cost.

Q. If I currently use Amazon EC2 Spot Fleet should I migrate to Amazon EC2 Fleet?

If you are leveraging Amazon EC2 Spot Instances with Spot Fleet, you can continue to use that. Spot Fleet and EC2 Fleet offer the same functionality. There is no requirement to migrate.

Q. Can I use Reserved Instance (RI) discounts with Amazon EC2 Fleet?

Yes, Similar to other EC2 APIs or other AWS services that launches EC2 instances, if the On-Demand instance launched by EC2 Fleet matches an existing RI, that instance will receive the RI discount. For example, if you own Regional RIs for M4 instances and you have specified only M4 instances in your EC2 Fleet, RI discounts will be automatically applied to this usage of M4.

Q. Will Amazon EC2 Fleet failover to On-Demand if EC2 Spot capacity is not fully fulfilled?

No, EC2 Fleet will continue to attempt to meet your desired Spot capacity based on the number of Spot instances you requested in your Fleet launch specification.

Q. What is the pricing for Amazon EC2 Fleet?

EC2 Fleet comes at no additional charge, you only pay for the underlying resources that EC2 Fleet launches.

Q. Can you provide a real world example of how I can use Amazon EC2 Fleet?

There are a number of ways to take advantage of Amazon EC2 Fleet, such as in big data workloads, containerized application, grid processing workloads etc. In this example of a genomic sequencing workload, you can launch a grid of worker nodes with a single API call: select your favorite instances, assign weights for these instances, specify target capacity for On-Demand and Spot Instances, and build a fleet within seconds to crunch through genomic data quickly.

Q. How can I allocate resources in an Amazon EC2 Fleet?

By default, EC2 Fleet will launch the On-Demand option that is lowest price. For Spot Instances, EC2 Fleet provides two allocation strategies: lowest price and diversified. The lowest price strategy allows you to provision Spot Instances in pools that provide the lowest price per unit of capacity at the time of the request. The diversified strategy allows you to provision Spot Instances across multiple Spot pools and you can maintain your fleet’s target capacity to increase application.

Q. Can I submit a multi-region Amazon EC2 Fleet request?

No, we do not support multi-region EC2 Fleet requests.

Q. Can I tag an Amazon EC2 Fleet?

Yes. You can tag a EC2 Fleet request to create business-relevant tag groupings to organize resources along technical, business, and security dimensions.

Q. Can I modify my Amazon EC2 Fleet?

Yes, you can modify the total target capacity of your EC2 Fleet when in maintain mode. You may need to cancel the request and submit a new one to change other request configuration parameters.

Q. Can I specify a different AMI for each instance type that I want to use?

Yes, simply specify the AMI you’d like to use in each launch specification you provide in your EC2 Fleet.

Q. What is a Spot Instance?

Spot instances are spare EC2 capacity that can save you up 90% off of On-Demand prices that AWS can interrupt with a 2-minute notification. Spot uses the same underlying EC2 instances as On-Demand and Reserved Instances, and is best suited for fault-tolerant, flexible workloads. Spot instances provides an additional option for obtaining compute capacity and can be used along with On-Demand and Reserved Instances.

Q. How is a Spot instance different than an On-Demand instance or Reserved Instance?

While running, Spot instances are exactly the same as On-Demand or Reserved instances. The main differences are that Spot instances typically offer a significant discount off the On-Demand prices, your instances can be interrupted by Amazon EC2 for capacity requirements with a 2-minute notification, and Spot prices adjust gradually based on long term supply and demand for spare EC2 capacity.

See here for more details on Spot instances.

Q. How do I purchase and start up a Spot instance?

Spot instances can be launched using the same tools you use launch instances today, including AWS Management Console, Auto-Scaling Groups, Run Instances and Spot Fleet. In addition many AWS services support launching Spot instances such as EMR, ECS, Datapipeline, Cloudformation and Batch.

To start up a Spot instance, you simply need to choose a Launch Template and the number of instances you would like to request.

See here for more details on how to request Spot instances.

Q. How many Spot instances can I request?

You can request Spot instances up to your Spot limit for each region. Note that customers new to AWS might start with a lower limit. To learn more about Spot instance limits, please refer to the Amazon EC2 User Guide.

If you would like a higher limit, complete the Amazon EC2 instance request form with your use case and your instance increase will be considered. Limit increases are tied to the region they were requested for.

Q. What price will I pay for a Spot instance?

You pay the Spot price that’s in effect at the beginning of each instance-hour for your running instance. If Spot price changes after you launch the instance, the new price is charged against the instance usage for the subsequent hour.

Q. What is a Spot capacity pool?

A Spot capacity pool is a set of unused EC2 instances with the same instance type, operating system, Availability Zone, and network platform (EC2-Classic or EC2-VPC). Each spot capacity pool can have a different price based on supply and demand.

Q. What are the best practices to use Spot instances?

We highly recommend using multiple Spot capacity pools to maximize the amount of Spot capacity available to you. EC2 provides built-in automation to find the most cost-effective capacity across multiple Spot capacity pools using Spot Fleet. For more information, please see Spot Best Practices.

Q. How can I determine the status of my Spot request?

You can determine the status of your Spot request via Spot Request Status code and message. You can access Spot Request Status information on the Spot Instance page of the EC2 console of the AWS Management Console, API and CLI. For more information, please visit the Amazon EC2 Developer guide.

Q. Are Spot instances available for all instance families and sizes and in all regions?

Spot instances are available in all public AWS regions. Spot is available for nearly all EC2 instance families and sizes, including the newest compute-optimized instances, accelerated graphics, and FPGA instance types. A full list of instance types supported in each region are listed here.

Q. Which operating systems are available as Spot instances?

Linux/UNIX and Windows Server are available. Windows Server with SQL Server is not currently available.

Q. Can I use a Spot instance with a paid AMI for third-party software (such as IBM’s software packages)?

Not at this time.

Q. When would my Spot instance get interrupted?

Over the last 3 months, 92% of Spot instance interruptions were from a customer manually terminating the instance because the application had completed its work.

In the circumstance EC2 needs to reclaim your Spot instance it can be for two possible reasons, with the primary one being Amazon EC2 capacity requirements (e.g. On Demand or Reserved Instance usage). Secondarily, if you have chosen to set a “maximum Spot price” and the Spot price rises above this, your instance will be reclaimed with a two-minute notification. This parameter determines the maximum price you would be willing to pay for a Spot instance hour, and by default, is set at the On-Demand price. As before, you continue to pay the Spot market price, not your maximum price, at the time your instance was running, charged in per-second increments.

Q. What happens to my Spot instance when it gets interrupted?

You can choose to have your Spot instances terminated, stopped or hibernated upon interruption. Stop and hibernate options are available for persistent Spot requests and Spot Fleets with the “maintain” option enabled. By default, your instances are terminated.

Refer to Spot Hibernation to learn more about handling interruptions.

Q. What is the difference between Stop and Hibernate interruption behaviors?

In the case of Hibernate, your instance gets hibernated and the RAM data persisted. In the case of Stop, your instance gets shutdown and RAM is cleared.

In both the cases, data from your EBS root volume and any attached EBS data volumes is persisted. Your private IP address remains the same, as does your elastic IP address (if applicable). The network layer behavior will be similar to that of EC2 Stop-Start workflow. Stop and Hibernate are available for Amazon EBS backed instances only. Local instance storage is not persisted.

Q. What if my EBS root volume is not large enough to store memory state (RAM) for Hibernate?

You should have sufficient space available on your EBS root volume to write data from memory. If the EBS root volume does not enough space, hibernation will fail and the instance will get shutdown instead. Ensure that your EBS volume is large enough to persist memory data before choosing the hibernate option.

Q. What is the benefit if Spot hibernates my instance on interruption?

With hibernate, Spot instances will pause and resume around any interruptions so your workloads can pick up from exactly where they left off. You can use hibernation when your instance(s) need to retain instance state across shutdown-startup cycles, i.e. when your applications running on Spot depend on contextual, business, or session data stored in RAM.

Q. What do I need to do to enable hibernation for my Spot instances?

Refer to Spot Hibernation to learn about enabling hibernation for your Spot instances.

Q. Do I have to pay for hibernating my Spot instance?

There is no additional charge for hibernating your instance beyond the EBS storage costs and any other EC2 resources you may be using. You are not charged instance usage fees once your instance is hibernated.

Q. Can I restart a stopped instance or resume a hibernated instance?

No, you will not be able to re-start a stopped instance or resume a hibernated instance directly. Stop-start and hibernate-resume cycles are controlled by Amazon EC2. If an instance is stopped or hibernated by Spot, it will be restarted or resumed by Amazon EC2 when the capacity becomes available.

Q. Which instances and operating systems support hibernation?

Spot Hibernation is currently supported for Amazon Linux AMIs, Ubuntu and Microsoft Windows operating systems running on any instance type across C3, C4, C5, M4, M5, R3, R4, R5 instances with memory (RAM) size less than 100 GiB.

To review the list of supported OS versions, refer to Spot Hibernation.

Q. How will I be charged if my Spot instance is interrupted?

If your Spot instance is terminated or stopped by Amazon EC2 in the first instance hour, you will not be charged for that usage. However, if you terminate the instance yourself, you will be charged to the nearest second. If the Spot instance is terminated or stopped by Amazon EC2 in any subsequent hour, you will be charged for your usage to the nearest second. If you are running on Windows and you terminate the instance yourself, you will be charged for an entire hour.

Q. How am I charged if Spot price changes while my instance is running? 

You will pay the price per instance-hour set at the beginning of each instance-hour for the entire hour, billed to the nearest second.

Q. Where can I see my usage history for Spot instances and see how much I was billed?

The AWS Management Console makes a detailed billing report available which shows Spot instance start and termination/stop times for all instances. Customers can check the billing report against historical Spot prices via the API to verify that the Spot price they were billed is correct.

Q: Are Spot blocks (Fixed Duration Spot instances) ever interrupted?

Spot blocks are designed not to be interrupted and will run continuously for the duration you select, independent of Spot market price. In rare situations, Spot blocks may be interrupted due to AWS capacity needs. In these cases, we will provide a two-minute warning before we terminate your instance (termination notice), and you will not be charged for the affected instance(s).

Q. What is a Spot fleet?

A Spot Fleet allows you to automatically request and manage multiple Spot instances that provide the lowest price per unit of capacity for your cluster or application, like a batch processing job, a Hadoop workflow, or an HPC grid computing job. You can include the instance types that your application can use. You define a target capacity based on your application needs (in units including instances, vCPUs, memory, storage, or network throughput) and update the target capacity after the fleet is launched. Spot fleets enable you to launch and maintain the target capacity, and to automatically request resources to replace any that are disrupted or manually terminated. Learn more about Spot fleets.

Q. Is there any additional charge for making Spot Fleet requests

No, there is no additional charge for Spot Fleet requests.

Q. What limits apply to a Spot Fleet request?

Visit the Spot Fleet Limits section of the Amazon EC2 User Guide to learn about the limits that apply to your Spot Fleet request.

Q. What happens if my Spot Fleet request tries to launch Spot instances but exceeds my regional Spot request limit?

If your Spot Fleet request exceeds your regional Spot instance request limit, individual Spot instance requests will fail with a Spot request limit exceeded request status. Your Spot Fleet request’s history will show any Spot request limit errors that the Fleet request received. Visit the Monitoring Your Spot Fleet section of the Amazon EC2 User Guide to learn how to describe your Spot Fleet request's history.

Q. Are Spot fleet requests guaranteed to be fulfilled?

No. Spot fleet requests allow you to place multiple Spot instance requests simultaneously, and are subject to the same availability and prices as a single Spot instance request. For example, if no resources are available for the instance types listed in your Spot Fleet request, we may be unable to fulfill your request partially or in full. We recommend you to include all the possible instance types and availability zones that are suitable for your workloads in the Spot Fleet.

Q. Can I submit a multi-Availability Zone Spot Fleet request?

Yes, visit the Spot Fleet Examples section of the Amazon EC2 User Guide to learn how to submit a multi-Availability Zone Spot Fleet request.

Q. Can I submit a multi-region Spot Fleet request?

No, we do not support multi-region Fleet requests.

Q. How does Spot Fleet allocate resources across the various Spot instance pools specified in the launch specifications?

The RequestSpotFleet API provides two allocation strategies: lowestPrice and diversified. The lowestPrice strategy allows you to provision your Spot Fleet resources in instance pools that provide the lowest price per unit of capacity at the time of the request. The diversified strategy allows you to provision your Spot Fleet resources across multiple Spot instance pools. This enables you to maintain your fleet’s target capacity and increase your application’s availability as Spot capacity fluctuates.

Running your application’s resources across diverse Spot instance pools also allows you to further reduce your fleet’s operating costs over time. Visit the Amazon EC2 User Guide to learn more.

Q. Can I tag a Spot Fleet request?

You can request to launch Spot instances with tags via Spot Fleet. The Fleet by itself cannot be tagged.

Q. How can I see which Spot fleet owns my Spot instances?

You can identify the Spot instances associated with your Spot Fleet by describing your fleet request. Fleet requests are available for 48 hours after all its Spot instances have been terminated. See the Amazon EC2 User Guide to learn how to describe your Spot Fleet request.

Q. Can I modify my Spot Fleet request?

Yes, you can modify the target capacity of your Spot Fleet request. You may need to cancel the request and submit a new one to change other request configuration parameters.

Q. Can I specify a different AMI for each instance type that I want to use?

Yes, simply specify the AMI you’d like to use in each launch specification you provide in your Spot Fleet request.

Q. Can I use Spot Fleet with Elastic Load Balancing, Auto Scaling, or Elastic MapReduce?

You can use Auto Scaling features with Spot Fleet such as target tracking, health checks, cloudwatch metrics etc and can attach instances to your Elastic load balancers (both classic and application load balancers). Elastic MapReduce has a feature named “Instance fleets” that provides capabilities similar to Spot Fleet.

Q. Does a Spot Fleet request terminate Spot instances when they are no longer running in the lowest priced Spot pools and relaunch them in the lowest priced pools?

No, Spot Fleet requests do not automatically terminate and re-launch instances while they are running. However, if you terminate a Spot instance, Spot Fleet will replenish it with a new Spot instance in the new lowest priced pool.

Q: Can I use stop or Hibernation interruption behaviors with Spot Fleet?

Yes, stop-start and hibernate-resume are supported with Spot Fleet with “maintain” fleet option enabled.

Q. How much compute power do Micro instances provide?

Micro instances provide a small amount of consistent CPU resources and allow you to burst CPU capacity up to 2 ECUs when additional cycles are available. They are well suited for lower throughput applications and web sites that consume significant compute cycles periodically but very little CPU at other times for background processes, daemons, etc. Learn more about use of this instance type.

Q. How does a Micro instance compare in compute power to a Standard Small instance?

At steady state, Micro instances receive a fraction of the compute resources that Small instances do. Therefore, if your application has compute-intensive or steady state needs we recommend using a Small instance (or larger, depending on your needs). However, Micro instances can periodically burst up to 2 ECUs (for short periods of time). This is double the number of ECUs available from a Standard Small instance. Therefore, if you have a relatively low throughput application or web site with an occasional need to consume significant compute cycles, we recommend using Micro instances.

Q. How can I tell if an application needs more CPU resources than a Micro instance is providing?

The CloudWatch metric for CPU utilization will report 100% utilization if the instance bursts so much that it exceeds its available CPU resources during that CloudWatch monitored minute. CloudWatch reporting 100% CPU utilization is your signal that you should consider scaling – manually or via Auto Scaling – up to a larger instance type or scale out to multiple Micro instances.

Q. Are all features of Amazon EC2 available for Micro instances?

Currently Amazon DevPay is not available for Micro instances.

Q. When should I use Compute Optimized instances?

Compute Optimized instances are designed for applications that benefit from high compute power. These applications include compute-intensive applications like high-performance web servers, high-performance computing (HPC), scientific modelling, distributed analytics and machine learning inference.

Q. Can I launch C4 instances as Amazon EBS-optimized instances?

Each C4 instance type is EBS-optimized by default. C4 instances 500 Mbps to 4,000 Mbps to EBS above and beyond the general-purpose network throughput provided to the instance. Since this feature is always enabled on C4 instances, launching a C4 instance explicitly as EBS-optimized will not affect the instance's behavior.

Q. How can I use the processor state control feature available on the c4.8xlarge instance?

The c4.8xlarge instance type provides the ability for an operating system to control processor C-states and P-states. This feature is currently available only on Linux instances. You may want to change C-state or P-state settings to increase processor performance consistency, reduce latency, or tune your instance for a specific workload. By default, Amazon Linux provides the highest-performance configuration that is optimal for most customer workloads; however, if your application would benefit from lower latency at the cost of higher single- or dual-core frequencies, or from lower-frequency sustained performance as opposed to bursty Turbo Boost frequencies, then you should consider experimenting with the C-state or P-state configuration options that are available to these instances. For additional information on this feature, see the Amazon EC2 User Guide section on Processor State Control.

Q. Which instances are available within Compute Optimized instances category?

C5 instances: C5 instances are the latest generation of EC2 Compute Optimized instances. C5 instances are based on Intel Xeon Platinum processors, part of the Intel Xeon Scalable (codenamed Skylake-SP) processor family, and are available in 6 sizes and offer up to 72 vCPUs and 144 GiB memory. C5 instances deliver 25% improvement in price/performance compared to C4 instances.

C5n instances: C5n instances offer significantly higher network performance across all the instance sizes, ranging from 25 Gbps of peak bandwidth on smaller instance sizes to 100 Gbps of network bandwidth on the largest instance size. C5n instances provide up to 33% more memory than the corresponding C5 instance sizes.

C4 instances: C4 instances are based on Intel Xeon E5-2666 v3 (codenamed Haswell) processors. C4 instances are available in 5 sizes and offer up to 36 vCPUs and 60 GiB memory.

Q. Should I move my workloads from C3 or C4 instances to C5 instances?

The generational improvement in CPU performance and lower price of C5 instances, which combined result in a 25% price/performance improvement relative to C4 instances, benefit a broad spectrum of workloads that currently run on C3 or C4 instances. For floating point intensive applications, Intel AVX-512 enables significant improvements in delivered TFLOPS by effectively extracting data level parallelism. Customers looking for absolute performance for graphics rendering and HPC workloads that can be accelerated with GPUs or FPGAs should also evaluate other instance families in the Amazon EC2 portfolio that include those resources to find the ideal instance for their workload.

Q. Which operating systems/AMIs are supported on C5 Instances?

EBS backed HVM AMIs with support for ENA networking and booting from NVMe-based storage can be used with C5 instances. The following AMIs are supported on C5:

• Amazon Linux 2014.03 or newer
• Ubuntu 14.04 or newer
• SUSE Linux Enterprise Server 12 or newer
• Red Hat Enterprise Linux 7.4 or newer
• CentOS 7 or newer
• Windows Server 2008 R2
  
• Windows Server 2012
• Windows Server 2012 R2
  
• Windows Server 2016
• FreeBSD 11.1-RELEASE

For optimal local NVMe-based SSD storage performance on C5d, Linux kernel version 4.9+ is recommended.

Q. What are the storage options available to C5 customers?

C5 instances use EBS volumes for storage, are EBS-optimized by default, and offer up to 9 Gbps throughput to both encrypted and unencrypted EBS volumes. C5 instances access EBS volumes via PCI attached NVM Express (NVMe) interfaces. NVMe is an efficient and scalable storage interface commonly used for flash based SSDs such as local NVMe storage provided with I3 instances. Though the NVMe interface may provide lower latency compared to Xen paravirtualized block devices, when used to access EBS volumes the volume type, size, and provisioned IOPS (if applicable) will determine the overall latency and throughput characteristics of the volume. When NVMe is used to provide EBS volumes, they are attached and detached by PCI hotplug.

C5d instances provide up to 3.6TB of SSD-based local NVMe storage. Customers looking to further boost the performance of their workloads, by using the local storage as a high-speed cache, can leverage C5d.

Q. What network interface is supported on C5 instances?

C5 instances use the Elastic Network Adapter (ENA) for networking and enable Enhanced Networking by default. With ENA, C5 instances can utilize up to 25 Gbps of network bandwidth.

Q. Which storage interface is supported on C5 instances?

C5 instances will support only NVMe EBS device model. EBS volumes attached to C5 instances will appear as NVMe devices. NVMe is a modern storage interface that provides latency reduction and results in increased disk I/O and throughput.

Q. How many EBS volumes can be attached to C5 instances?

C5 instances support a maximum for 27 EBS volumes for all Operating systems. The limit is shared with ENI attachments which can be found here http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html. For example: since every instance has at least 1 ENI, if you have 3 additional ENI attachments on the c4.2xlarge, you can attach 24 EBS volumes to that instance.

Q. What is the underlying hypervisor on C5 instances?

C5 instances use a new EC2 hypervisor that is based on core KVM technology.

Q: Why does the total memory reported by Linux not match the advertised memory of the C5 instance type?

In C5, portions of the total memory for an instance are reserved from use by the Operating System including areas used by the virtual BIOS for things like ACPI tables and for devices like the virtual video RAM.

Q: What are Accelerated Computing instances?

Accelerated Computing instances use hardware accelerators, or co-processors, to perform some functions, such as floating-point number calculation and graphics processing, more efficiently than is possible in software running on CPUs. Amazon EC2 provides three types of Accelerated Computing instances – GPU compute instances for machine learning and HPC, GPU graphics instances for graphics intensive applications, and FPGA programmable hardware compute instances for advanced scientific workloads.

Q. When should I use GPU Graphics and Compute instances?

GPU instances work best for applications with massive parallelism such as workloads using thousands of threads. Graphics processing is an example with huge computational requirements, where each of the tasks is relatively small, the set of operations performed form a pipeline, and the throughput of this pipeline is more important than the latency of the individual operations. To be able to build applications that exploit this level of parallelism, one needs GPU device specific knowledge by understanding how to program against various graphics APIs (DirectX, OpenGL) or GPU compute programming models (CUDA, OpenCL).

Q: How are P3 instances different from G3 instances?

P3 instances are EC2 GPU computing instances targeted at machine learning and HPC applications, powered by up to 8 of the latest-generation NVIDIA Tesla V100 GPUs. These instances significantly improve performance and scalability, and have many features, including a Streaming Multiprocessor (SM) architecture for machine learning (ML)/deep learning (DL) performance optimization, second-generation NVIDIA NVLink high-speed GPU interconnect, and highly tuned HBM2 memory for higher-efficiency.

G3 instances use NVIDIA Tesla M60 GPUs and provide a high-performance platform for graphics applications using DirectX or OpenGL. NVIDIA Tesla M60 GPUs support NVIDIA GRID Virtual Workstation features, and H.265 (HEVC) hardware encoding. Each M60 GPU in G3 instances supports 4 monitors with resolutions up to 4096x2160, and is licensed to use NVIDIA GRID Virtual Workstation for one Concurrent Connected User. Example applications of G3 instances include 3D visualizations, graphics-intensive remote workstations, 3D rendering, application streaming, video encoding, and other server-side graphics workloads.

Q: What are the benefits of NVIDIA Volta GV100 GPUs?

The NVIDIA Tesla V100 accelerator incorporates the powerful Volta GV100 GPU. GV100 not only builds upon the advances of its predecessor, the Pascal GP100 GPU, it significantly improves performance and scalability, and adds many features that improve programmability. These advances supercharge HPC, data center, supercomputer, and deep learning systems and applications.

Q: Who benefits from P3 instances?

P3 instances with their high computational performance benefit users in artificial intelligence (AI), machine learning (ML), deep learning (DL) and high performance computing (HPC) applications. Users include data scientists, data architects, data analysts, scientific researchers, ML engineers, IT managers and software developers. Key industries include transportation, energy/oil & gas, financial services (banking, insurance), healthcare, pharmaceutical, sciences, IT, retail, manufacturing, high-tech, transportation, government, academia, among many others.

Q: What are some key use cases of P3 instances?

P3 instances use GPUs to accelerate numerous deep learning systems and applications including autonomous vehicle platforms, speech, image, and text recognition systems, intelligent video analytics, molecular simulations, drug discovery, disease diagnosis, weather forecasting, big data analytics, financial modeling, robotics, factory automation, real-time language translation, online search optimizations, and personalized user recommendations, to name just a few.

Q: Why should customers use GPU-powered Amazon P3 instances for AI/ML and HPC?

GPU-based compute instances provide greater throughput and performance because they are designed for massively parallel processing using thousands of specialized cores per GPU, versus CPUs offering sequential processing with a few cores. In addition, developers have built hundreds of GPU-optimized scientific HPC applications such as quantum chemistry, molecular dynamics, meteorology, among many others. Research indicates that over 70% of the most popular HPC applications provide built-in support for GPUs.

Q: Do P3 instances support EC2 Classic networking and Amazon VPC?

P3 instances support VPC only.

Q. How are G3 instances different from P2 instances?

G3 instances use NVIDIA Tesla M60 GPUs and provide a high-performance platform for graphics applications using DirectX or OpenGL. NVIDIA Tesla M60 GPUs support NVIDIA GRID Virtual Workstation features, and H.265 (HEVC) hardware encoding. Each M60 GPU in G3 instances supports 4 monitors with resolutions up to 4096x2160, and is licensed to use NVIDIA GRID Virtual Workstation for one Concurrent Connected User. Example applications of G3 instances include 3D visualizations, graphics-intensive remote workstation, 3D rendering, application streaming, video encoding, and other server-side graphics workloads.

P2 instances use NVIDIA Tesla K80 GPUs and are designed for general purpose GPU computing using the CUDA or OpenCL programming models. P2 instances provide customers with high bandwidth 25 Gbps networking, powerful single and double precision floating-point capabilities, and error-correcting code (ECC) memory, making them ideal for deep learning, high performance databases, computational fluid dynamics, computational finance, seismic analysis, molecular modeling, genomics, rendering, and other server-side GPU compute workloads.

Q: How are P3 instances different from P2 instances?

P3 Instances are the next-generation of EC2 GPU computing instances, powered by up to 8 of the latest-generation NVIDIA Volta GV100 GPUs. These instances significantly improve performance and scalability and add many new features, including new Streaming Multiprocessor (SM) architecture, optimized for machine learning (ML)/deep learning (DL) performance, second-generation NVIDIA NVLink high-speed GPU interconnect, and highly tuned HBM2 memory for higher-efficiency.

P2 instances use NVIDIA Tesla K80 GPUs and are designed for general purpose GPU computing using the CUDA or OpenCL programming models. P2 instances provide customers with high bandwidth 25 Gbps networking, powerful single and double precision floating-point capabilities, and error-correcting code (ECC) memory.

Q. What APIs and programming models are supported by GPU Graphics and Compute instances?

P3 instances support CUDA 9 and OpenCL, P2 instances support CUDA 8 and OpenCL 1.2 and G3 instances support DirectX 12, OpenGL 4.5, CUDA 8, and OpenCL 1.2.

Q. Where do I get NVIDIA drivers for P3 and G3 instances?

There are two methods by which NVIDIA drivers may be obtained. There are listings on the AWS Marketplace which offer Amazon Linux AMIs and Windows Server AMIs with NVIDIA drivers pre-installed. You may also launch 64-bit, HVM AMIs and install the drivers yourself. You must visit the NVIDIA driver website and search for the NVIDIA Tesla V100 for P3, NVIDIA Tesla K80 for P2, and NVIDIA Tesla M60 for G3 instances.

Q. Which AMIs can I use with P3, P2 and G3 instances?

You can currently use Windows Server, SUSE Enterprise Linux, Ubuntu, and Amazon Linux AMIs on P2 and G3 instances. P3 instances only support HVM AMIs. If you want to launch AMIs with operating systems not listed here, contact AWS Customer Support with your request or reach out through EC2 Forums.

Q. Does the use of G2 and G3 instances require third-party licenses?

Aside from the NVIDIA drivers and GRID SDK, the use of G2 and G3 instances does not necessarily require any third-party licenses. However, you are responsible for determining whether your content or technology used on G2 and G3 instances requires any additional licensing. For example, if you are streaming content you may need licenses for some or all of that content. If you are using third-party technology such as operating systems, audio and/or video encoders, and decoders from Microsoft, Thomson, Fraunhofer IIS, Sisvel S.p.A., MPEG-LA, and Coding Technologies, please consult these providers to determine if a license is required. For example, if you leverage the on-board h.264 video encoder on the NVIDIA GRID GPU you should reach out to MPEG-LA for guidance, and if you use mp3 technology you should contact Thomson for guidance.

Q. Why am I not getting NVIDIA GRID features on G3 instances using the driver downloaded from NVIDIA website?

The NVIDIA Tesla M60 GPU used in G3 instances requires a special NVIDIA GRID driver to enable all advanced graphics features and 4 monitor support with resolution up to 4096x2160. You need to use an AMI with NVIDIA GRID driver pre-installed, or download and install the NVIDIA GRID driver following the AWS documentation.

Q. Why am I unable to see the GPU when using Microsoft Remote Desktop?

When using Remote Desktop, GPUs using the WDDM driver model are replaced with a non-accelerated Remote Desktop display driver. In order to access your GPU hardware, you need to utilize a different remote access tool, such as VNC.

Q. What is Amazon EC2 F1?

Amazon EC2 F1 is a compute instance with programmable hardware you can use for application acceleration. The F1 instance type provides a high performance, easy to access FPGA for developing and deploying custom hardware accelerations.

Q. What are FPGAs and why do I need them?

FPGAs are programmable integrated circuits that you can configure using software. By using FPGAs you can accelerate your applications by up to 30x when compared with servers that use CPUs alone. And, FPGAs are reprogrammable, so you get the flexibility to update and optimize your hardware acceleration without having to redesign the hardware.

Q. How does F1 compare with traditional FPGA solutions?

F1 is an AWS instance with programmable hardware for application acceleration. With F1, you have access to FPGA hardware in a few simple clicks, reducing the time and cost of full-cycle FPGA development and scale deployment from months or years to days. While FPGA technology has been available for decades, adoption of application acceleration has struggled to be successful in both the development of accelerators and the business model of selling custom hardware for traditional enterprises, due to time and cost in development infrastructure, hardware design, and at-scale deployment. With this offering, customers avoid the undifferentiated heavy lifting associated with developing FPGAs in on-premises data centers.

Q: What is an Amazon FPGA Image (AFI)?

The design that you create to program your FPGA is called an Amazon FPGA Image (AFI). AWS provides a service to register, manage, copy, query, and delete AFIs. After an AFI is created, it can be loaded on a running F1 instance. You can load multiple AFIs to the same F1 instance, and can switch between AFIs in runtime without reboot. This lets you quickly test and run multiple hardware accelerations in rapid sequence. You can also offer to other customers on the AWS Marketplace a combination of your FPGA acceleration and an AMI with custom software or AFI drivers.

Q. How do I list my hardware acceleration on the AWS Marketplace?

You first develop your AFI and the software drivers/tools to use this AFI. You would then package these software tools/drivers into an Amazon Machine Image (AMI) in an encrypted format. AWS manages all AFIs in the encrypted format you provide to maintain the security of your code. To sell a product in the AWS Marketplace, you or your company must sign up to be an AWS Marketplace reseller. You would then submit your AMI ID and the AFI ID(s) intended to be packaged in a single product. AWS Marketplace will take care of cloning the AMI and AFI(s) to create a product, and associate a product code to these artifacts, such that any end-user subscribing to this product code would have access to the AMI and the AFI(s).

Q. What is available with F1 instances?

For developers, AWS provides a Hardware Development Kit (HDK) to help accelerate development cycles, an FPGA Developer AMI for development in the cloud, an SDK for AMIs running the F1 instance, and a set of APIs to register, manage, copy, query, and delete AFIs. Both developers and customers have access to the AWS Marketplace where AFIs can be listed and purchased for use in application accelerations.

Q. Do I need to be an FPGA expert to use an F1 instance?

AWS customers subscribing to an F1-optimized AMI from AWS Marketplace do not need to know anything about FPGAs to take advantage of the accelerations provided by the F1 instance and the AWS Marketplace. Simply subscribe to an F1-optimized AMI from the AWS Marketplace with an acceleration that matches the workload. The AMI contains all the software necessary for using the FPGA acceleration. Customers need only write software to the specific API for that accelerator and start using the accelerator.

Q. I’m an FPGA developer, how do I get started with F1 instances?

Developers can get started on an F1 instance by creating an AWS account and downloading the AWS Hardware Development Kit (HDK). The HDK includes documentation on F1, internal FPGA interfaces, and compiler scripts for generating AFIs. Developers can start writing their FPGA code to the documented interfaces included in the HDK to create their acceleration function. Developers can launch AWS instances with the FPGA Developer AMI. This AMI includes the development tools needed to compile and simulate the FPGA code. The Developer AMI is best run on the latest C5, M5, or R5 instances. Developers should have experience in the programming languages used for creating FPGA code (i.e. Verilog or VHDL) and an understanding of the operation they wish to accelerate.

Q. I’m not an FPGA developer, how do I get started with F1 instances?

Customers can get started with F1 instances by selecting an accelerator from the AWS Marketplace, provided by AWS Marketplace sellers, and launching an F1 instance with that AMI. The AMI includes all of the software and APIs for that accelerator. AWS manages programming the FPGA with the AFI for that accelerator. Customers do not need any FPGA experience or knowledge to use these accelerators. They can work completely at the software API level for that accelerator.

Q. Does AWS provide a developer kit?

Yes. The Hardware Development Kit (HDK) includes simulation tools and simulation models for developers to simulate, debug, build, and register their acceleration code. The HDK includes code samples, compile scripts, debug interfaces, and many other tools you will need to develop the FPGA code for your F1 instances. You can use the HDK either in an AWS provided AMI, or in your on-premises development environment. These models and scripts are available publically with an AWS account.

Q. Can I use the HDK in my on-premises development environment?

Yes. You can use the Hardware Development Kit either in an AWS-provided AMI, or in your on-premises development environment.

Q. Can I add an FPGA to any EC2 instance type?

No. F1 instances come in three instance sizes f1.2xlarge, f1.4xlarge, and f1.16xlarge. 

Q. What is a Cluster Compute Instance?

Cluster Compute Instances combine high compute resources with a high performance networking for High Performance Compute (HPC) applications and other demanding network-bound applications. Cluster Compute Instances provide similar functionality to other Amazon EC2 instances but have been specifically engineered to provide high performance networking.

Amazon EC2 cluster placement group functionality allows users to group Cluster Compute Instances in clusters – allowing applications to get the low-latency network performance necessary for tightly-coupled node-to-node communication typical of many HPC applications. Cluster Compute Instances also provide significantly increased network throughput both within the Amazon EC2 environment and to the Internet. As a result, these instances are also well suited for customer applications that need to perform network-intensive operations.

Learn more about use of this instance type for HPC applications.

Q. What kind of network performance can I expect when I launch instances in cluster placement group?

The bandwidth an EC2 instance can utilize in a cluster placement group depends on the instance type and its networking performance specification. Inter-instance traffic within the same region can utilize 5 Gbps for single-flow and up to 100 Gbps for multi-flow traffic. When launched in a placement group, select EC2 instances can utilize up to 10 Gbps for single-flow traffic.

Q. What is a Cluster GPU Instance?

Cluster GPU Instances provide general-purpose graphics processing units (GPUs) with proportionally high CPU and increased network performance for applications benefiting from highly parallelized processing that can be accelerated by GPUs using the CUDA and OpenCL programming models. Common applications include modeling and simulation, rendering and media processing.

Cluster GPU Instances give customers with HPC workloads an option beyond Cluster Compute Instances to further customize their high performance clusters in the cloud for applications that can benefit from the parallel computing power of GPUs.

Cluster GPU Instances use the same cluster placement group functionality as Cluster Compute Instances for grouping instances into clusters – allowing applications to get the low-latency, high bandwidth network performance required for tightly-coupled node-to-node communication typical of many HPC applications.

Learn more about HPC on AWS.

Q. What is a High Memory Cluster Instance?

High Memory Cluster Instances provide customers with large amounts of memory and CPU capabilities per instance in addition to high network capabilities. These instance types are ideal for memory intensive workloads including in-memory analytics systems, graph analysis and many science and engineering applications

High Memory Cluster Instances use the same cluster placement group functionality as Cluster Compute Instances for grouping instances into clusters – allowing applications to get the low-latency, high bandwidth network performance required for tightly-coupled node-to-node communication typical of many HPC and other network intensive applications.

Q. Does use of Cluster Compute and Cluster GPU Instances differ from other Amazon EC2 instance types?

Cluster Compute and Cluster GPU Instances use differs from other Amazon EC2 instance types in two ways.

First, Cluster Compute and Cluster GPU Instances use Hardware Virtual Machine (HVM) based virtualization and run only Amazon Machine Images (AMIs) based on HVM virtualization. Paravirtual Machine (PVM) based AMIs used with other Amazon EC2 instance types cannot be used with Cluster Compute or Cluster GPU Instances.

Second, in order to fully benefit from the available low latency, full bisection bandwidth between instances, Cluster Compute and Cluster GPU Instances must be launched into a cluster placement group through the Amazon EC2 API or AWS Management Console.

Q. What is a cluster placement group?

A cluster placement group is a logical entity that enables creating a cluster of instances by launching instances as part of a group. The cluster of instances then provides low latency connectivity between instances in the group. Cluster placement groups are created through the Amazon EC2 API or AWS Management Console.

Q. Are all features of Amazon EC2 available for Cluster Compute and Cluster GPU Instances?

Currently, Amazon DevPay is not available for Cluster Compute or Cluster GPU Instances.

Q. Is there a limit on the number of Cluster Compute or Cluster GPU Instances I can use and/or the size of cluster I can create by launching Cluster Compute Instances or Cluster GPU into a cluster placement group?

There is no limit specific for Cluster Compute Instances. For Cluster GPU Instances, you can launch 2 Instances on your own. If you need more capacity, please complete the Amazon EC2 instance request form (selecting the appropriate primary instance type).

Q. Are there any ways to optimize the likelihood that I receive the full number of instances I request for my cluster via a cluster placement group?

We recommend that you launch the minimum number of instances required to participate in a cluster in a single launch. For very large clusters, you should launch multiple placement groups, e.g. two placement groups of 128 instances, and combine them to create a larger, 256 instance cluster.

Q. Can Cluster GPU and Cluster Compute Instances be launched into a single cluster placement group?

While it may be possible to launch different cluster instance types into a single placement group, at this time we only support homogenous placement groups.

Q. If an instance in a cluster placement group is stopped then started again, will it maintain its presence in the cluster placement group?

Yes. A stopped instance will be started as part of the cluster placement group it was in when it stopped. If capacity is not available for it to start within its cluster placement group, the start will fail.

Q: What are Amazon EC2 A1 instances?

Amazon EC2 A1 instances are new general purpose instances powered by the AWS Graviton Processors that are custom designed by AWS.

Q: What are the specifications of the new AWS Graviton Processors?

AWS Graviton processors are a new line of processors that are custom designed by AWS utilizing Amazon’s extensive expertise in building platform solutions for cloud applications running at scale. These processors are based on the 64-bit Arm instruction set and feature Arm Neoverse cores as well as custom silicon designed by AWS. The cores operate at a frequency of 2.3 GHz.

Q: When should I use A1 instances?

A1 instances deliver significant cost savings for customer workloads that are supported by the extensive Arm ecosystem and can fit within the available memory footprint. A1 instances are ideal for scale-out applications such as web servers, containerized microservices, caching fleets, and distributed data stores. These instances will also appeal to developers, enthusiasts, and educators across the Arm developer community. Most applications that make use of open source software like Apache HTTP Server, Perl, PHP, Ruby, Python, NodeJS, and Java easily run on multiple processor architectures due to the support of Linux based operating systems. We encourage customers running such applications to give A1 instances a try.

Applications that require higher compute and network performance, require higher memory, or have dependencies on x86 architecture will be better suited for existing instances like the M5, C5, or R5 instances. Applications with variable CPU usage that experience occasional spikes in demand will get the most cost savings from the burstable performance T3 instances.

Q: Will customers have to modify applications and workloads to be able to run on the A1 instances?

The changes required are dependent on the application. Applications based on interpreted or run-time compiled languages (e.g. Python, Java, PHP, Node.js) should run without modifications. Other applications may need to be recompiled and those that don't rely on x86 instructions will generally build with minimal to no changes.

Q: Which operating systems/AMIs are supported on A1 Instances?

The following AMIs are supported on A1 instances: Amazon Linux 2, Ubuntu 16.04.4 or newer, Red Hat Enterprise Linux (RHEL) 7.6 or newer. EBS backed HVM AMIs launched on A1 instances require NVMe and ENA drivers installed at instance launch.

Q: Are there specific AMI requirements to run on A1 instances?

You will want to ensure that you use the “arm64” AMIs with the A1 instances. x86 AMIs are not compatible with A1 instances.

Q: What are the various storage options available to A1 customers?

A1 instances are EBS-optimized by default and offer up to 3,500 Mbps of dedicated EBS bandwidth to both encrypted and unencrypted EBS volumes. A1 instances only support Non-Volatile Memory Express (NVMe) interface to access EBS storage volumes. A1 instances will not support the blkfront interface.

Q: Which network interface is supported on A1 instances?

A1 instances support ENA based Enhanced Networking. With ENA, A1 instances can deliver up to 10 Gbps of network bandwidth between instances when launched within a Placement Group.

Q: Do A1 instances support the AWS Nitro System?

Yes, A1 instances will be powered by the AWS Nitro System, a combination of dedicated hardware and Nitro hypervisor.

Q: Why does the total memory reported by Linux not match the advertised memory of the A1 instance type?

In A1 instances, portions of the total memory for an instance are reserved from use by the operating system including areas used by the virtual UEFI for things like ACPI tables.

Q: What are the key use cases for Amazon EC2 M5 Instances?

M5 instances offer a good choice for running development and test environments, web, mobile and gaming applications, analytics applications, and business critical applications including ERP, HR, CRM, and collaboration apps. Customers who are interested in running their data intensive workloads (e.g. HPC, or SOLR clusters) on instances with a higher memory footprint will also find M5 to be a good fit. Workloads that heavily use single and double precision floating point operations and vector processing such as video processing workloads and need higher memory can benefit substantially from the AVX-512 instructions that M5 supports.

Q: Why should customers choose EC2 M5 Instances over EC2 M4 Instances?

Compared with EC2 M4 Instances, the new EC2 M5 Instances deliver customers greater compute and storage performance, larger instance sizes for less cost, consistency and security. The biggest benefit of EC2 M5 Instances is based on its usage of the latest generation of Intel Xeon Scalable processors (aka Skylake), which deliver up to 20% improvement in price/performance compared to M4. With AVX-512 support in M5 vs. the older AVX2 in M4, customers will gain 2x higher performance in workloads requiring floating point operations. M5 instances offer up to 25 Gbps of network bandwidth and up to 10 Gbps of dedicated bandwidth to Amazon EBS. M5 instances also feature significantly higher networking and Amazon EBS performance on smaller instance sizes with EBS burst capability.

Q: How does support for Intel AVX-512 benefit EC2 M5 and M5d Instance customers?

Intel Advanced Vector Extension 512 (AVX-512) is a set of new CPU instructions available on the latest Intel Xeon Scalable processor family, that can accelerate performance for workloads and usages such as scientific simulations, financial analytics, artificial intelligence, machine learning/deep learning, 3D modeling and analysis, image and video processing, cryptography and data compression, among others. Intel AVX-512 offers exceptional processing of encryption algorithms, helping to reduce the performance overhead for cryptography, which means EC2 M5 and M5d customers can deploy more secure data and services into distributed environments without compromising performance

Q: What are the various processor options available to M5 customers?

The M5 and M5d instance types use a 3.1 GHz Intel Xeon Platinum 8