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You're slightly off in your understanding of VCPUs. All AWS instances "get" VCPUs. A VCPU is a single thread in architectures with SMT and a single core in arch

by paol 2y ago

You're slightly off in your understanding of VCPUs. All AWS instances "get" VCPUs. A VCPU is a single thread in architectures with SMT and a single core in architectures without. So for example c7a instances which are AMD EPYCs have 1 VCPU = 1/2 core. They have is a page that lists this for every single instance type which I can't be bothered to search for right now. As for spot instances, they're a great if you can use them, but you can't hold their price as being representative. Now using savings plan prices as representative is defensible, but it won't bring the cost below the "hundreds per month" order of magnitude.

phonon 2y ago
Hyperthreading is turned off on m7a/c7a/r7a. "One of the major differences between M7a instances and the previous generations of instances, such as M6a instances, is their vCPU to physical processor core mapping. Every vCPU on a M7a instance is a physical CPU core. This means there is no Simultaneous Multi-Threading (SMT). By contrast, every vCPU on prior generations such as M6a instances is a thread of a CPU core." https://aws.amazon.com/ec2/instance-types/m7a/ https://aws.amazon.com/ec2/instance-types/m7a/
- paol 2y ago
  > Hyperthreading is turned off on m7a/c7a/r7a. You made me go check and you're right! Thanks for the correction.