How does Hyper-V manage the core allocation with an Intel i9-13900(k)?

M's 0 Reputation points
2023-02-04T20:01:31.4033333+00:00

Hi, I'm planning to build a new PC where I have to run multiple virtual machines at the same time.

I was thinking to use an i9-13900 (k or not) because of its 24 cores but I just realized that it has Performance Cores and Efficiency Cores so how does HyperV manage the core allocation with such architecture?

And another thing about the core allocation that I didn't understand very well is if I can allocate to a virtual machine only up to the maximum number of cores of the CPU, for example I actually have a CPU with 4 cores and 8 threads so I can allocate up to 4 cores or can I go beyond 4 until I reach 8 because it has 8 threads?

Thanks for the help.

Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
2,473 questions
0 comments No comments
{count} votes

3 answers

Sort by: Most helpful
  1. Limitless Technology 44,011 Reputation points
    2023-02-06T15:56:01.9366667+00:00

    Hello there,

    A virtual machine’s vCPU count means the maximum number of threads that the VM can run at any given moment.

    Generally, it's recommended to set 8 vCPUs per 1 physical core.

    This article describes Hyper-V resource and isolation controls for virtual machines. These capabilities, which we'll refer to as Virtual Machine CPU Groups, or just "CPU groups", were introduced in Windows Server 2016. https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/manage/manage-hyper-v-cpugroups

    Hope this resolves your Query !!

    --If the reply is helpful, please Upvote and Accept it as an answer–


  2. Dave Patrick 426.1K Reputation points MVP
    2023-02-07T23:49:30.22+00:00

    You can over-allocate up to a point. Read on here.

    https://www.altaro.com/hyper-v/hyper-v-virtual-cpus-explained/

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    

    --please don't forget to upvote and Accept as answer if the reply is helpful--


  3. Dave Patrick 426.1K Reputation points MVP
    2023-02-09T16:45:21.2166667+00:00

    If you try to allocate more cores than the host has you'll get something like below when you try to start it up.

    User's image

    --please don't forget to upvote and Accept as answer if the reply is helpful--