Vcpu limit in ec2 instances


when i check in my service quota ec2 limit for Running On-Demand Standard (A, C, D, H, I, M, R, T, Z) instances is by default is showing 5.

in ec2 docs on-demand instance vcpu limit showing as => You can launch any combination of instance types that meet your changing application needs, as long as the number of vCPUs does not exceed your account quota. For example, with a Standard instance quota of 256 vCPUs, you could launch 32 m5.2xlarge instances (32 x 8 vCPUs) or 16 c5.4xlarge instances (16 x 16 vCPUs).

in ec2 faq it shows as below.

How many On-Demand Instances can I run in Amazon EC2?

There are five vCPU-based instance limits; each defines the amount of capacity you can use of a given instance family. All usage of instances in a given family, regardless of generation, size, or configuration variant (e.g. disk, processor type), will accrue towards the family’s total vCPU limit, listed in the table below. New AWS accounts may start with limits that are lower than the limits described here. On-Demand Instance Limit Name Default vCPU Limit Running On-Demand Standard (A, C, D, H, I, M, R, T, Z) instances 1152 vCPUs Running On-Demand F instances 128 vCPUs Running On-Demand G instances 128 vCPUs Running On-Demand Inf instances 128 vCPUs Running On-Demand P instances 128 vCPUs Running On-Demand X instances 128 vCPUs

so my question is which one is right can someone please also tell me what is vcpu limit actually means and if it support 1152vpu then i can launch more than 20 instance (t3.small). which is another limitation.

asked 5 months ago440 views
1 Answer


EC2's vCPU limit is the total vCPU.
For example, in order to start multiple instance types (A, C, D, H, I, M, R, T, Z), you cannot start them unless the number of vCPUs is less than the quota.

If 1152vpu is set in the quota, it is calculated that up to 576 EC2s of "t3.small" can be started.
However, if you start "t3.small" up to the limit of 1152vpu, the instances (A, C, D, H, I, M, R, T, Z) cannot be started.

The columns listed in the table below are quotas.

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answered 5 months ago

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