How do I request an EC2 vCPU limit increase for my On-Demand Instance?

Short description

You submit EC2 vCPU limit increases as a vCPU value. To request an increase, first determine the number of vCPUs that your On-Demand Instances use. Then, compare this number against vCPU-based limits. Use this information to determine the appropriate service limit increase to request.

Resolution

Example calculations

Before you request a service limit increase, calculate the vCPU value that you need for your use case. See the following example scenarios and their calculations.

Scenario 1: You're not currently running any G family instances. You want to launch three g4dn.xlarge instances.

Your current vCPU limit is Running On-Demand All G instances = 8 vCPU.

A g4dn.xlarge instance has a footprint of 4 vCPUs. Your account can already run two g4dn.xlarge instances, based on your G instances limit of 8.

In this scenario, submit a vCPU service limit increase request for 12 vCPUs (3*4).

Format your request as follows:

Limit type: EC2 Instances
Region: US West
Primary Instance Type: Running On-Demand All G instances
New limit value: 12

Note: Replace US West with the AWS Region where you're requesting a limit increase.

Scenario 2: You're currently running 64 vCPUs worth of instances. You want to launch two additional m5.2xlarge and two additional m4.10xlarge instance types.

Your current vCPU limit is Running On-Demand All Standard (A, C, D, H, I, M, R, T, Z) instances = 64 vCPU.

Both instance types that you want to launch are included in the "All Standard (A, C, D, H, I, M, R, T, Z) instances" limit. Usage for these instance types is added together and governed by a single limit. The instance-to-vCPU conversion rates for these two types of instances are as follows:

• *.2xlarge instances = 8 vCPU per instance
• *.10xlarge instances = 40 vCPU per instance.

Therefore, the additional number of vCPUs needed is calculated as follows:

[2 * 8] + [2 * 40] = 96.

You need 96 additional vCPUs if your account is already running 64 vCPUs worth of instances.

In this scenario, submit a vCPU service limit increase request for 160 vCPUs (64 + 96) or higher.

Format your request as follows:

Limit type: EC2 Instances
Region: US West
Primary Instance Type: Running On-Demand All Standard (A, C, D, H, I, M, R, T, Z) instances
New limit value: 160

Note: Replace US West with the Region you're requesting a limit increase in.

Scenario 3: You want to test more powerful instance types, but you don't know which instances you need. Therefore, your service limit increase request needs to provide you flexibility.

Your current vCPU limit is Running On-Demand All P instances = 64 vCPU.

The vCPUs of an instance within a family can range from 1 to 128 vCPUs, depending on the size. vCPU limits give you the versatility to start with one instance type, and then switch to another instance type without submitting a new limit increase, as long as you stay within your vCPU limit.

For example, you might request a combination of P instance types:

• Five p3.2xlarge instances, 8 vCPU per instance = 40 vCPU
• One of the largest P-Family instance type, the p3dn.24xlarge, 96 vCPU per instance = 96 vCPU

In this scenario, to keep your limit request small while retaining flexibility, submit a request for 136 vCPU (40 + 96).

Format your request as follows:

Limit type: EC2 Instances
Region: US West
Primary Instance Type: Running On-Demand All P instances
New limit value: 136

Note: Replace US West with the Region that you're requesting a limit increase in.

To streamline the processing of your limit increase request, in the Use case description section of the request form, include specific instance types. For example, include p3.8xlarge or p3dn.24xlarge. Also, note whether you're expecting to use the different instances in parallel or one at a time.

Request an On-Demand Instance limit increase

You can request an increase to your Amazon EC2 service quotas (formerly called service limits) with either the AWS Support dashboard or Service Quotas dashboard.

AWS Support dashboard

1. Open the AWS Support dashboard.
2. Choose Looking for service limit increases?
   Important: EC2 service quotas affect one Region at a time. You must request service quota increases in each AWS Region where you need more resources.
3. (Optional) To request multiple service quota increases at the same time, complete one quota increase request in the Requests section, and then choose Add another request.

Service Quotas dashboard

1. Open the Service Quotas dashboard.
2. Choose Amazon Elastic Compute Cloud (Amazon EC2).
3. Choose the required service quota for your instance type.
4. Choose Request quota increase.

Related information

On-demand Instances

Troubleshooting instance launch issues