Improved Intel Turbo Boost status/control

John john at
Tue Mar 13 20:22:07 UTC 2012

>I found that setting performance_cpu_freq="HIGH" doesn't work on my
>desktop system, I guess because devd never gets any AC adapter events
>that trigger running the power_profile script.  I enabled it manually by
>adding these lines to my /etc/sysctl.conf:
>  hw.acpi.cpu.cx_lowest=C2
>  dev.cpu.0.freq=3334
>It would be nice to come up with a way to automatically enable this for
>desktop users.  If not fully automatic, hopefully require no more than a
>simple =YES knob in rc.conf.

I applied the patch to 2 desktop machines and added performance_cpu_freq="HIGH"
to rc.conf:

8.3-PRERELEASE #3 r232864M: Mon Mar 12 16:11:47 PDT 2012
dev.cpu.0.freq: 2927
dev.cpu.0.freq_levels: 2927/95000 2926/95000 2793/78000 2660/70000 ...

9.0-STABLE FreeBSD 9.0-STABLE #0 r232923M: Tue Mar 13 10:06:33 PDT 2012
dev.cpu.0.freq: 3301
dev.cpu.0.freq_levels: 3301/95000 3300/95000 3100/87000 2900/80000 ...

so it appears to be working for me automatically.

John Theus
TheUs Group

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