Dedicated Instances - Amazon Elastic Compute Cloud

Dedicated Instances

Dedicated Instances are Amazon EC2 instances that run in a virtual private cloud (VPC) on hardware that's dedicated to a single customer. Dedicated Instances that belong to different AWS accounts are physically isolated at a hardware level, even if those accounts are linked to a single payer account. However, Dedicated Instances might share hardware with other instances from the same AWS account that are not Dedicated Instances.

Note

A Dedicated Host is also a physical server that's dedicated for your use. With a Dedicated Host, you have visibility and control over how instances are placed on the server. For more information, see Dedicated Hosts.

Dedicated Instance basics

Dedicated Instances can be launched into an Amazon VPC only.

When you launch an instance, the instance's tenancy attribute determines the hardware that it runs on. To launch a Dedicated Instance, you must specify an instance tenancy of dedicated.

Note

Instances with a tenancy value of default run on shared tenancy hardware. Instances with a tenancy value of host run on a Dedicated Host. For more information about working with Dedicated Hosts, see Dedicated Hosts.

The tenancy of the VPC into which you launch the instance can also determine the instance's tenancy. A VPC can have a tenancy of either default or dedicated. If you launch an instance into a VPC that has a tenancy of default, the instance runs on shared tenancy hardware by default, unless you specify a different tenancy for the instance. If you launch an instance into a VPC that has a tenancy of dedicated, the instance runs as a Dedicated Instance by default, unless you specify a different tenancy for the instance.

To launch Dedicated Instances, you can do the following:

Supported features

Dedicated Instances support the following features and AWS service integrations:

Reserved Instances

To guarantee that sufficient capacity is available to launch Dedicated Instances, you can purchase Dedicated Reserved Instances. For more information, see Reserved Instances.

When you purchase a Dedicated Reserved Instance, you are purchasing the capacity to launch a Dedicated Instance into a VPC at a much reduced usage fee; the price break in the usage charge applies only if you launch an instance with dedicated tenancy. When you purchase a Reserved Instance with default tenancy, it applies only to a running instance with default tenancy; it does not apply to a running instance with dedicated tenancy.

You can't use the modification process to change the tenancy of a Reserved Instance after you've purchased it. However, you can exchange a Convertible Reserved Instance for a new Convertible Reserved Instance with a different tenancy.

Automatic scaling

You can use Amazon EC2 Auto Scaling to launch Dedicated Instances. For more information, see Launching Auto Scaling Instances in a VPC in the Amazon EC2 Auto Scaling User Guide.

Automatic recovery

You can configure automatic recovery for a Dedicated Instance if it becomes impaired due to an underlying hardware failure or a problem that requires AWS involvement to repair. For more information, see Recover your instance.

Dedicated Spot Instances

You can run a Dedicated Spot Instance by specifying a tenancy of dedicated when you create a Spot Instance request. For more information, see Specify a tenancy for your Spot Instances.

Burstable performance instances

You can leverage the benefits of running on dedicated tenancy hardware with Burstable performance instances. T3 Dedicated Instances launch in unlimited mode by default, and they provide a baseline level of CPU performance with the ability to burst to a higher CPU level when required by your workload. The T3 baseline performance and ability to burst are governed by CPU credits. Because of the burstable nature of the T3 instance types, we recommend that you monitor how your T3 instances use the CPU resources of the dedicated hardware for the best performance. T3 Dedicated Instances are intended for customers with diverse workloads that display random CPU behavior, but that ideally have average CPU usage at or below the baseline usages. For more information, see Key concepts and definitions for burstable performance instances.

Amazon EC2 has systems in place to identify and correct variability in performance. However, it is still possible to experience short-term variability if you launch multiple T3 Dedicated Instances that have correlated CPU usage patterns. For these more demanding or correlated workloads, we recommend using M5 or M5a Dedicated Instances rather than T3 Dedicated Instances.

Differences between Dedicated Instances and Dedicated Hosts

Dedicated Instances and Dedicated Hosts can both be used to launch Amazon EC2 instances onto physical servers that are dedicated for your use.

There are no performance, security, or physical differences between Dedicated Instances and instances on Dedicated Hosts. However, there are some differences between the two. The following table highlights some of the key differences between Dedicated Instances and Dedicated Hosts:

Dedicated Host Dedicated Instance

Billing

Per-host billing

Per-instance billing

Visibility of sockets, cores, and host ID

Provides visibility of the number of sockets and physical cores on the host

No visibility

Host and instance affinity

Allows you to consistently deploy your instances onto the same host over time

Not supported

Targeted instance placement

Provides control over how instances are placed on the host

Not supported

Automatic instance recovery

Supported

Supported

Bring Your Own License (BYOL)

Supported

Not supported

For more information about Dedicated Hosts, see Dedicated Hosts.

Dedicated Instances limitations

Keep the following in mind when using Dedicated Instances:

  • Some AWS services or their features are not supported with a VPC with the instance tenancy set to dedicated. Refer to the respective service's documentation to confirm if there are any limitations.

  • Some instance types can't be launched into a VPC with the instance tenancy set to dedicated. For more information about supported instance types, see Amazon EC2 Dedicated Instances.

  • When you launch a Dedicated Instance backed by Amazon EBS, the EBS volume doesn't run on single-tenant hardware.

Pricing for Dedicated Instances

Pricing for Dedicated Instances is different from pricing for On-Demand Instances. For more information, see the Amazon EC2 Dedicated Instances product page.