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I'm using a laptop with bad cooling system, so my CPU sometimes hits very high temperature, and linux kernel is able to throttle cpu clock to cool it as I can see in dmesg:

[22612.245243] CPU3: Core temperature above threshold, cpu clock throttled (total events = 617268)
...
[22612.257307] CPU3: Core temperature/speed normal
etc

Lately, I installed FreeBSD to play with it and I noticed that it uses CPU at full speed all the time, even when I set powerd to -a hiadaptive -b adaptive -i 85 -r 60 -p 100, so after some usage CPU temp goes above normal and FreeBSD just restarts instead of throttling. I also tried to use C-states but it doesn't helped.

How can I configure it to get linux behavior?

  • 1
    All the hardware is different, you should probably give some more details about your box -- does it have coretemp or other drivers showing the CPU temperature, what is the processor, dmesg etc. Unfortunately, very few people run FreeBSD on the laptop, so, I don't think there's any general and obvious solution here. Perhaps it's just a matter of the power-saving features not being supported for your CPU or chipset? – cnst Feb 8 '16 at 2:14
  • Well, coretemp is enabled, and it shows the temperature, the CPU is i7-2640M, where can I look up supported CPUs power-saving controls? I've checked powerd, it shows no messages about that. By the way, is there an userland utility to control cpu frequency? I think I should be able to write a shell script to throttle on temperature. – Ivan Chebykin Feb 8 '16 at 8:50
  • Hmm, I've checked again through the dev.cpu.0.freq, even if I disable powerd and set frequency to minimum, temperature will still be at 80 degrees. – Ivan Chebykin Feb 8 '16 at 9:33
  • 1
    Might not be supported; best to ask on the freebsd mailing lists, including the full dmesg and appropriate sysctl output. Also, I may suggest trying out DragonFly BSD and OpenBSD, to see if that may solve the problem? On OpenBSD, you'd use sysctl hw.setperf to control CPU, and OpenBSD is actually much more popular on laptops than FreeBSD. Also, DragonFly did some power experiments recently, and results were very surprising! See lists.dragonflybsd.org/pipermail/users/2015-July/207911.html lobste.rs/s/vidxex – cnst Feb 8 '16 at 17:15
  • Have you tried with powerdxx package? it's better with multiple cores. – raspi Sep 28 '18 at 23:34

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