Pentium III / i815 - powersaving possible?

[Peter Ganzhorn]

Erik Mouw wrote:
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>   
Sorry for that, I just thought this might be the lazy way...won't happen 
again!
> On Mon, Jul 23, 2007 at 11:51:43PM +0200, Peter Ganzhorn wrote:
>   
>> in order to get a temporary fileserver running at home, I "reactivated" an 
>> old Pentium III on a i815-based board.
>>     
>
> I have one running as a personal video recorder (MythTV), but it gets a
> bit rusty so it's due to be replaced by a modern core2 duo machine.
>
>   
>> Combined with a gigabit NIC this box works perfectly as a file server, but 
>> I wondered if there is a way to reduce the power consumption of this box 
>> when running.
>> Even for earlier Intel chipsets (e.g. the 440BX) there are CPUfreq drivers 
>> available in the kernel, but I wasn't able to find any driver suitable for 
>> the i815.
>> Is there a CPUfreq driver that can save me some power on this box?
>>     
>
> I'm afraid not. For frequency and voltage scaling to work, both the CPU
> and the chipset have to support it. IIRC only some mobile PIII support
> scaling, and only when the chipset supports it as well.
>
>   
>> AFAIK it does not support C-states at all, so this is the only way I can 
>> think of to save some power.
>>     
>
> I guess it will support C states, my equally old Athlon 1.6 GHz also
> supports it. Even if it doesn't support C states you can still save
> power by letting it idle as much as possible.
>
>
> Erik
>
>   
Thanks for the hints, I'll check if it supports C-states - combined with 
dynticks this already helps a lot I guess.

Peter