Instance types

When you launch an instance, the instance type that you specify determines the hardware of the host computer used for your instance. Each instance type offers different compute, memory, and storage capabilities, and is grouped in an instance family based on these capabilities. Select an instance type based on the requirements of the application or software that you plan to run on your instance.

Amazon EC2 dedicates some resources of the host computer, such as CPU, memory, and instance storage, to a particular instance. Amazon EC2 shares other resources of the host computer, such as the network and the disk subsystem, among instances. If each instance on a host computer tries to use as much of one of these shared resources as possible, each receives an equal share of that resource. However, when a resource is underused, an instance can consume a higher share of that resource while it's available.

Each instance type provides higher or lower minimum performance from a shared resource. For example, instance types with high I/O performance have a larger allocation of shared resources. Allocating a larger share of shared resources also reduces the variance of I/O performance. For most applications, moderate I/O performance is more than enough. However, for applications that require greater or more consistent I/O performance, consider an instance type with higher I/O performance.

Instance type names

Amazon EC2 provides a variety of instance types so you can choose the type that best meets your requirements. Instance types are named based on their family, generation, additional capabilities, and size. The first position of the instance type name indicates the instance family, for example c. The second position indicates the instance generation, for example 5. The remaining letters before the period indicate additional capabilities, such as instance store volumes. After the period (.) is the instance size, which is either a number followed by a size, such as 9xlarge, or metal for bare metal instances.

The following are the additional capabilities indicated by the instance type names:

• a – AMD processors

• g – AWS Graviton processors

• i – Intel processors

Contents

Available instance types

Amazon EC2 provides a wide selection of instance types optimized to fit different use cases. Instance types comprise varying combinations of CPU, memory, storage, and networking capacity and give you the flexibility to choose the appropriate mix of resources for your applications. Each instance type includes one or more instance sizes, allowing you to scale your resources to the requirements of your target workload.

Note

Previous generation instances are still fully supported and retain the same features and functionality. We encourage you to use the latest generation of instances to get the best performance.

To determine which instance types meet your requirements, such as supported Regions, compute resources, or storage resources, see .

Topics

Current generation instances

For the best performance, we recommend that you use the following instance types when you launch new instances. For more information, see .

Sixth and seventh generation of Amazon EC2 instances

Sixth and seventh generation instances include:

• General purpose: M6a, M6g, M6gd, M6i, M6id, M6idn, M6in, M7g, T4g

• Computer optimized: C6a, C6g, C6gd, C6gn, C6i, C6id, C6in, C7g, Hpc6a

• Memory optimized: Hpc6id, R6a, R6g, R6gd, R6i, R6id, R6idn, R6in, R7g, X2gd, X2idn, X2iedn

Instances

General purpose

Compute optimized

Memory optimized

Storage optimized

Accelerated computing

Previous generation instances

Amazon Web Services offers previous generation instance types for users who have optimized their applications around them and have yet to upgrade. We encourage you to use current generation instance types to get the best performance, but we continue to support the following previous generation instance types. For more information about which current generation instance type would be a suitable upgrade, see .

Hardware specifications

For more information, see .

To determine which instance type best meets your needs, we recommend that you launch an instance and use your own benchmark application. Because you pay by the instance second, it's convenient and inexpensive to test multiple instance types before making a decision. If your needs change, even after you make a decision, you can change the instance type later. For more information, see .

Processor features

Intel processor features

Amazon EC2 instances that run on Intel processors may include the following features. Not all of the following processor features are supported by all instance types. For detailed information about which features are available for each instance type, see

• Intel AES New Instructions (AES-NI) — Intel AES-NI encryption instruction set improves upon the original Advanced Encryption Standard (AES) algorithm to provide faster data protection and greater security. All current generation EC2 instances support this processor feature.

• Intel Advanced Vector Extensions (Intel AVX, Intel AVX2, and Intel AVX-512) — Intel AVX and Intel AVX2 are 256-bit, and Intel AVX-512 is a 512-bit instruction set extension designed for applications that are Floating Point (FP) intensive. Intel AVX instructions improve performance for applications like image and audio/video processing, scientific simulations, financial analytics, and 3D modeling and analysis. These features are only available on instances launched with HVM AMIs.

Confusion may result from industry naming conventions for 64-bit CPUs. Chip manufacturer Advanced Micro Devices (AMD) introduced the first commercially successful 64-bit architecture based on the Intel x86 instruction set. Consequently, the architecture is widely referred to as AMD64 regardless of the chip manufacturer. Windows and several Linux distributions follow this practice. This explains why the internal system information on an instance running Ubuntu or Windows displays the CPU architecture as AMD64 even though the instances are running on Intel hardware.

AMI virtualization types

The virtualization type of your instance is determined by the AMI that you use to launch it. Current generation instance types support hardware virtual machine (HVM) only. Some previous generation instance types support paravirtual (PV) and some AWS Regions support PV instances. For more information, see .

For best performance, we recommend that you use an HVM AMI. In addition, HVM AMIs are required to take advantage of enhanced networking. HVM virtualization uses hardware-assist technology provided by the AWS platform. With HVM virtualization, the guest VM runs as if it were on a native hardware platform, except that it still uses PV network and storage drivers for improved performance.

Instances built on the Nitro System

The Nitro System is a collection of hardware and software components built by AWS that enable high performance, high availability, and high security. For more information, see .

The Nitro System provides bare metal capabilities that eliminate virtualization overhead and support workloads that require full access to host hardware. Bare metal instances are well suited for the following:

• Workloads that require access to low-level hardware features (for example, Intel VT) that are not available or fully supported in virtualized environments

• Applications that require a non-virtualized environment for licensing or support

Nitro components

The following components are part of the Nitro System:

• Nitro card

  • Local NVMe storage volumes

  • Networking hardware support

Virtualized instances

The following virtualized instances are built on the Nitro System:

• General purpose: A1, M5, M5a, M5ad, M5d, M5dn, M5n, M5zn, M6a, M6g, M6gd, M6i, M6id, M6idn, M6in, M7g, T3, T3a, and T4g

• Compute optimized: C5, C5a, C5ad, C5d, C5n, C6a, C6g, C6gd, C6gn, C6i, C6id, C6in, C7g, and Hpc6a

• Memory optimized: Hpc6id, R5, R5a, R5ad, R5b, R5d, R5dn, R5n, R6a, R6g, R6gd, R6i, R6idn, R6in, R6id, R7g, U-3tb1, U-6tb1, U-9tb1, U-12tb1, X2gd, X2idn, X2iedn, X2iezn, and z1d

Bare metal instances

The following bare metal instances are built on the Nitro System:

• General purpose: a1.metal | m5.metal | m5d.metal | m5dn.metal | m5n.metal | m5zn.metal | m6a.metal | m6g.metal | m6gd.metal | m6i.metal | m6id.metal

Learn more

For more information, see the following videos:

Networking and storage features

When you select an instance type, this determines the networking and storage features that are available. To describe an instance type, use the command.

Networking features

• IPv6 is supported on all current generation instance types and the C3, R3, and I2 previous generation instance types.

• To maximize the networking and bandwidth performance of your instance type, you can do the following:

  • Launch supported instance types into a cluster placement group to optimize your instances for high performance computing (HPC) applications. Instances in a common cluster placement group can benefit from high-bandwidth, low-latency networking. For more information, see

Storage features

• Some instance types support EBS volumes and instance store volumes, while other instance types support only EBS volumes. Some instance types that support instance store volumes use solid state drives (SSD) to deliver very high random I/O performance. Some instance types support NVMe instance store volumes. Some instance types support NVMe EBS volumes. For more information, see and .

• To obtain additional, dedicated capacity for Amazon EBS I/O, you can launch some instance types as EBS–optimized instances. Some instance types are EBS–optimized by default. For more information, see .

Summary of networking and storage features

The following table summarizes the networking and storage features supported by current generation instance types.

Instances

General purpose

Compute optimized

Memory optimized

Storage optimized

Accelerated computing

Previous generation instance types

The following table summarizes the networking and storage features supported by previous generation instance types.

Instance limits

There is a limit on the total number of instances that you can launch in a Region, and there are additional limits on some instance types.

For more information about the default limits, see

For more information about viewing your current limits or requesting an increase in your current limits, see .