Amd Ryzen7 5825U (zen3) : tunning frequency?

[jlm]

Hi
After some research I finished to find how to set AMD ryzen frequency using cpupower
but I'm a little disapointed

I disabled boost mode, because too noisy

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echo "0" > /sys/devices/system/cpu/cpufreq/boost

made a rc service file and applied it at boot.

I used the "power save" performance preference setting (

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/sys/devices/system/cpu/cpu*/cpufreq/energy_performance_preference

) and the CPU frequency reported by cpupower was always stuck @2Ghz while current overall cpu usage was below 17% (in power save it should be able to go from 1,4Ghz to 2Ghz

so I tried lowest power mode

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# echo "power" | tee /sys/devices/system/cpu/cpu*/cpufreq/energy_performance_preference

now cpupower reports me 1,4Ghz, so this means that I'm able to change the frequency but cpu usage is still below 26%
cpupower reports

amd-pstate limits:
Highest Performance: 166. Maximum Frequency: 4.55 GHz.
Nominal Performance: 73. Nominal Frequency: 2.00 GHz.
Lowest Non-linear Performance: 40. Lowest Non-linear Frequency: 1.10 GHz.
Lowest Performance: 15. Lowest Frequency: 400 MHz.
Preferred Core Support: 1. Preferred Core Ranking: 191.

I would like to go below the 1,4GHz because the fan is still on and I don't see why keeping the CPU running fast while there is no activity

the driver is amd-pstate-epp
scaling_governor is powersave
hardware limitation is : 411 MHz - 2.00 GHz

cpu ad some tunning parameters like

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SYSFS_EXTRA="ondemand/ignore_nice_load=1 ondemand/up_threshold=75 ondemand/sampling_down_factor=10"

but seems they aren't working anymore with amd-pstate driver, so maybe I should change driver? because the pstate driver seems broken always running at fastest allowed frequency

thanks for your help

[krumpf]

A couple years ago, amd-pstate minimal frequency has been tweaked for SoC (and all others CPU), see this MR : https://gitlab.freedesktop.org/upower/p ... quests/198
I noticed the same behavior on my desktop ryzen, the lowest frequency used to be 550MHz, and got switched to 1743 MHz.