C-state, P-state, ACPI... still guest CPU is not scaling

[bellocarico]

My CPUs (Opteron 4280) is capable of

Frequency	2800 MHz
Maximum turbo frequency	3100 MHz (more than 4 cores) 3500 MHz (4 cores or less)

I have 14 cores assigned to a Windows 10 VMs according and to task manager this run constantly at 2.8GHz no matter if idle or encoding videos. Tried ESXi Power management to Balanced and high Performance = same result

I have compared task manager on my local PC and I can see  the frequency instead changes constantly based on the usage.

Does anybody have a good idea on how to take the most of my CPUs when it comes to ESXi 6.5 and CPU scaling/boosting? perhaps changing further the BIOS settings of my tyan S8225?

p.s. I currently have C6 + C1E + ACPI + PowerNow + P0 state enabled

Thanks!

[dariusd]

I have no information or sources to back this up, but I would suspect that your host's power policy determines the host's CPU performance states, but the host CPU performance information most likely is not fed back to the virtual CPU and made visible to the guest... In other words, perhaps you are getting the most out of your host CPUs (running at full/turbo speeds) but the guest OS is oblivious...?

Like I said, I've no evidence for/against that, but that is what I would expect based upon the bits and pieces I know of our CPU emulation.

--

Darius