Arch Linux

MajinJoko

Member

Registered: 2007-08-15

Posts: 84

Cannot limit cpu frequency

Dear all,
this is the output of cpupower frequency-info:

$ cpupower frequency-info
analisi della CPU 0:
  driver: intel_pstate
  CPU che operano alla stessa frequenza hardware: 0
  CPU che è necessario siano coordinate dal software: 0
  latenza massima durante la transizione:  Cannot determine or is not supported.
  limiti hardware: 800 MHz - 3.00 GHz
  gestori disponibili: performance powersave
  gestore attuale: la frequenza deve mantenersi tra 800 MHz e 1.80 GHz.
                   Il gestore "powersave" può decidere quale velocità usare
                  in questo intervallo.
  current CPU frequency: 1.29 GHz (asserted by call to hardware)
  boost state support:
    Supported: yes
    Active: yes
    2800 MHz max turbo 4 active cores
    2800 MHz max turbo 3 active cores
    2800 MHz max turbo 2 active cores
    3000 MHz max turbo 1 active cores

I can limit the cpu frequency:

$ cpupower frequency-set -u 800000
Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3

..or, I think I can.

What actually happens is that the limit seems to hold until I am in gnome or surfing the web with chrome (the system seems slower and laggy!), but as soon as I start a game (Rocket League) that limit is.. broken?
This is what I see:

$ cpupower frequency-info
analisi della CPU 0:
  driver: intel_pstate
  CPU che operano alla stessa frequenza hardware: 0
  CPU che è necessario siano coordinate dal software: 0
  latenza massima durante la transizione:  Cannot determine or is not supported.
  limiti hardware: 800 MHz - 3.00 GHz
  gestori disponibili: performance powersave
  gestore attuale: la frequenza deve mantenersi tra 800 MHz e 800 MHz.
                   Il gestore "powersave" può decidere quale velocità usare
                  in questo intervallo.
  current CPU frequency: 2.49 GHz (asserted by call to hardware)
  boost state support:
    Supported: yes
    Active: yes
    2800 MHz max turbo 4 active cores
    2800 MHz max turbo 3 active cores
    2800 MHz max turbo 2 active cores
    3000 MHz max turbo 1 active cores

As you can see, the current frequency is far above the 800MHz limit set.

Is this some expected beheaviour? Am I really able to limit the cpu frequency?

Thanks for any hint!

ps: my system is an up to date Archlinux.

x33a

Forum Fellow

Registered: 2009-08-15

Posts: 4,587

Re: Cannot limit cpu frequency

Please edit your post and use LC_ALL=C with all the commands.

https://wiki.archlinux.org/index.php/Co … s_and_code

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,344

Re: Cannot limit cpu frequency

Does /sys/devices/system/cpu/cpu0/cpufreq/scaling_[min|max]_freq change at any time and to what values?

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