Re: CPU power management

[Mattia Dongili <malattia@linux.it>]

On Thu, Feb 15, 2007 at 11:26:24PM +0200, Eddy Petri??or wrote:
[...]
> I have installed Debian GNU/kFreeBSD and indeed, the levels are many
> more than on Linux:
> 
> sysctl dev.cpu.0.freq_levels
> 
> Results in a list of frequencies down to 31 MHz. I tried some script I
> found on the freebsd lists[1] to test the speed of blowfish at various
> speeds and observed that on my Core 2 Duo that:
[...]
> In conclusion, it would be nice if this code would be ported to Linux, too.

AFAICT they are mixing freq scaling and throttling.
See /proc/acpi/processor/CPU[01]/throttling, I have:

state count:             8
active state:            T0
states:
   *T0:                  00%
    T1:                  12%
    T2:                  25%
    T3:                  37%
    T4:                  50%
    T5:                  62%
    T6:                  75%
    T7:                  87%

and the available frequency steps here are 1.83 GHz, 1.33 GHz, 1000 MHz
This is a Core2 Duo T5600.

so eg. at 1GHz I can throttle at 880, 750, 630, 500, 380, 250 and
130 MHz.

-- 
mattia
:wq!