Re: CPU power management
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Mattia Dongili wrote:
> On Sun, Feb 18, 2007 at 02:49:28AM +0200, Eddy Petri??or wrote:
>> Mattia Dongili wrote:
> ...
>>>> See /proc/acpi/processor/CPU[01]/throttling, I have:
>> Is that on Linux or kFreeBSD?
>
> the above quoted /proc entry is Linux, the one who is mixing scaling and
> throttling is FreeBSD.
>
> ...
>>> Oh, and let me add (even if probably aready mentioned): throttling
>>> doesn't save any power, it just idles your cpu. Ok, less heat (no fans,
>>> etc) but the real saving is probably unnoticeable.
>> Taking into account that my laptop almost all the time heats up even
>> if scaled down to 50% (1GHz/minimum) in Linux, thus triggering
>> periodic fan runs at regular intervals, which, of course, leads to
>> more power consumption, I'd welcome throttling .... although I don't
>> know if it would make any difference taking into account my laptop
>> always runs at 1GHz when on battery.
>
> well, the backside is that eg. building a kernel will take twice running
> with the cpu throttled at 50%.
Well, I don't plan to do any kernel building while on battery and I
am sure that a proper set of patches would allow me to configure
when I want throttling i.e. I could configure cpufreqd or whomever
to have throttling disabled while on AC and enabled while on battery
;-).
> I haven't any measurement but I'm pretty sure you can find something
> online (especially related to the P4 clock modulation which only allows
> throttling, and in this regard I'm in favour of throttling too as my
> desktop's P4 heats very fast).
TBH, I am not that keen to look for such things as long as I can't
benefit from the results :-/
- --
Regards,
EddyP
=============================================
"Imagination is more important than knowledge" A.Einstein
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