[TUTORIAL] Low CPU Frequency on guest VM (even on high load)


New Member
Jul 9, 2023
I was having some problems with my current setup using gpu passthrough on a Windows Guest VM, in random moments my CPU Frequency would drop to the bare minimum for minutes at a time without any logical explanation, acpi is disabled on BIOS and the guest VM was gaming at the time, so performance would drop considerably.
Screenshot 2023-07-30 120855.png
After some tweaking I set the cpu affinity of the vm to cores 20-23 and the problem still occurred at random times, with the help of cpufreq-set I just changed the minfreq and governor of said CPUs and the problem disappeared, I still don't know what causes the host to slow down the clock even though that's the cpu the VM is currently using, but just changing the governor to performance still didn't solve the issue, the minfreq needed to be changed too:

cpufreq-set --cpu 20-23 --min 3200Mhz --g "performance"

Screenshot 2023-07-30 121248.png

Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz
this problem only occured on this host, I have other installations and that's the first time i've seen this weird behavior
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