[Bug 215729] amd-pstate driver has a much higher idle power consumption for a desktop Zen 3 CPU

[bugzilla-daemon@kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=215729

--- Comment #9 from Artem S. Tashkinov (aros@gmx.com) ---
(In reply to Joe from comment #8)
> Hello,
> 
> I reproduce this issue on my local.  
> 
> Your device (CPU family:  25, Model:  33) should be shared memory solution
> with AMD P-state driver. Updating CPPC request with shared memory will need
> more energy  than writing MSR register directly. We are checking this issue
> now.
> 
> For ondemand governor, could you please try to reduce the sampling_rate and
> then check to energy consumption again? Thanks a lot!
> 
> Here is the command 
> 
> cd /sys/devices/system/cpu/cpufreq/ondemand
> echo 50000 > sampling_rate
> 
> Thanks
> Joe

Changing sampling_rate from default 2000 to 50000 has improved the situation
considerably but still acpi-cpufreq has a tiny better idle power consumption.

acpi-cpufreq: ~20W
amd-pstate with default ondemand settings: ~23W
amd-pstate with ondemand/sampling_rate=50k: ~21W

Looks like the ondemand scheduler is not super efficient with the amd-pstate
driver.

-- 
You may reply to this email to add a comment.

You are receiving this mail because:
You are the assignee for the bug.