How to use AMD P-State in Linux

just comment it if you did not already. Michael usually reads the comments and adds things if he also finds it useful/interesting.

phoronix forums are a cesspool lol

I avoid them like the plague

Ryzen 7700X definitely looking sexy:

cpupower frequency-info                             
analyzing CPU 0:
  driver: amd-pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 131 us
  hardware limits: 400 MHz - 5.57 GHz
  available cpufreq governors: conservative ondemand userspace powersave performance schedutil
  current policy: frequency should be within 400 MHz and 5.57 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 969 MHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes
    AMD PSTATE Highest Performance: 166. Maximum Frequency: 5.57 GHz.
    AMD PSTATE Nominal Performance: 134. Nominal Frequency: 4.50 GHz.
    AMD PSTATE Lowest Non-linear Performance: 89. Lowest Non-linear Frequency: 2.99 GHz.
    AMD PSTATE Lowest Performance: 12. Lowest Frequency: 400 MHz.
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Not fair!

Edit: I jealous now! :wink:

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Just upgrade :wink:
My take on the situation: (at release, not true now) Ryzen 7000..Good Performance, Poor Value - #17 by BS86

I already bought a 5800x :slightly_frowning_face:

Thats terrible advice for someone with a 5000 series CPU lol absolutely not worth it in 95% of scenerios but thats for another thread.

then why frown? you have a great system already, youre not missing out or anything.

Anyone been experiencing some performance issues in 6.0 Kernels with P-State on desktop Ryzen 5000? Ive been having some weird performance issues with it. Ill randomly get hard FPS drops in games for instance with no real reason it should be happening.

Are you using Shared Mem? If you are, there are performance issues.
https://www.kernel.org/doc/html/latest/admin-guide/pm/amd-pstate.html#kernel-module-options-for-amd-pstate

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one can not use AMD P-state without shared mem …

The linked kernel docs state shared mem is an optional module parameter. If your cpu supports full msr that kernel option is not needed

I know there are technically issues, but Ive been using it already its only recently that performance got weird, im trying to see if its just my setup or anyone else is seeing it.

Ive been running p state since 5.17 (i posted this thread lol), its only since 6.0 its been weird

you can if your CPU supports the registers for it, i think Ryzen 7000 and laptop 4000(some)/5000/6000 should be able to. Would you be able to check if P State works on 7000 series without shared memory enabled so i could update the OP for 7000 series?

My 3800X is running great on X570 platform. My 5800X is going in the B550 platform.

will do tonight, currently at work with no access to my system at home.

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cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver  
amd-pstate

It is indeed working without shared mem

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awesome, thank you for taking a moment to test it :grin:

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Can you confirm if you see CPU usage spikes ?

I have been monitoring my CPU usage for a few days now, and after reading the info above, I decided to disable amd_pstate and now I’m back to acpi-cpufreq and schedutil.

As soon as I changed it, my CPU usage is now considerably lower than it was with amd_pstate while doing my daily tasks…

Depending how much of an enthusiast you are there’s a new version coming down the pipe. Probably not in mainline kernel until 6.2 but if you’re savvy enough you could build your own kernel and add the patchset yourself
https://bbs.archlinux.org/viewtopic.php?pid=2062998#p2062998
https://www.phoronix.com/news/AMD-P-State-EPP-Linux-v2

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