2

New CPUs (at least in the consumer market) will eventually likely all have the split into performance and efficient cores that Intel has started with the 12000 series.

I have seen some bad/dumb scheduling and frequency boosting (or not boosting) in the past, so my I wonder:

Does Hyper-V properly/efficiently schedule and assign slow and fast cores to guest VMs, using a heuristic? Or does it pass the information slow/fast to the guest OS (still burdening the user to properly assign fast/slow cores)? If so, starting with a particular version?

This is about Hyper-V and Windows Server in a small office professional environment. Virtualizing on client Windows 11 is not an option.

As for a similar question, Does the hybrid CPU architecture pose any new issues for VM's, or VM software like VMware, or VirtualBox? :

This question is about Windows Client, not Windows Server. The Intel link given in the accepted answer https://www.intel.com/content/www/us/en/gaming/resources/how-hybrid-design-works.html seems very "opinionated" by Intel. It says that the hybrid technology works perfect with any OS. Strangely, changes to Windows 11 were needed and the search engine of one's choice will report issues with all hybrid generations (not just limited to the 12th generation).

Finally, virtualization seems to be a reasonably hard thing to do performance-wise. At least on 1 machine I had the issues that the guests were maxed out but the host did not increase it's clock speed (like it should have) with Hyper-V 2016 and a small Dell PowerEdge.

Also, https://en.wikipedia.org/wiki/Windows_Server_2022 states that Windows Server 2022 still is based on Windows 10 and not Windows 11 (which also seems likely, given that previous Windows Server versions also always had the same UI changes as the equivalent client OS).

Improve this question
8
  • 2
    Does this answer your question? Does the hybrid CPU architecture pose any new issues for VM's, or VM software like VMware, or VirtualBox?
    – harrymc
    Commented Jan 31, 2023 at 16:50
  • @harrymc No, that is an answer to a similar but other question. It does not answer my question! The answer does not even distinguish between host and guest. (On top it is over-simplified if you know a little about core assignment in hypervisors, see e. g. flackbox.com/… .)
    – Andreas Reiff
    Commented Jan 31, 2023 at 18:54
  • Your paper does not address this question at all. It's mostly for ESXi, which is its own operating system. When running under Windows, Hyper-V leaves core assignment to the host. The vCPUs are just threads running inside the Windows. Performance/Efficiency core assignment cannot be handled by Hyper-V, since it requires a too-tight integration and ownership with the physical CPU. Windows 11 was built for it.
    – harrymc
    Commented Jan 31, 2023 at 20:00
  • No, it does not address that question but is about core to VM assignment - otherwise I wouldn't have asked but just read that. I put the link here to show that the answer in the other thread seems to be lacking in depth - apart from not addressing my issue. Since you seem to know more about that: isn't Windows Server 2022 similar to Windows 11? Or will a future Server/Hyper-V be? Hence there would be a chance for tighter integration. And having VMs unwantedly scheduled on E-Cores would give bad performance. Also right now Hyper-V does not peek much into guests, or so it seems.
    – Andreas Reiff
    Commented Jan 31, 2023 at 20:11
  • Also, doesn't Windows 11 get it's ability to handle that from inspecting running applications - something that would be very hard host to guest? I read in the interesting article I posted :) that Hyper-V relies on specific guests having certain abilities that help with scheduling (in that context it is about synchronisation when cores (threads?) are run sequentially due to lack of free cores).
    – Andreas Reiff
    Commented Jan 31, 2023 at 20:14

0

Reset to default

You must log in to answer this question.

Browse other questions tagged .