Re: CPU power management

[Florian Reitmeir <florian@reitmeir.org>]

On Die, 06 Feb 2007, Eddy Petri??or wrote:

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> Florian Reitmeir wrote:
> > On Mon, 05 Feb 2007, Eddy Petri??or wrote:
> > 
> > But indeed its possible to "undervolt" the cpu to save power, approx. 10-20%,
> > search for the linux-phc patches.
> > 
> > https://www.dedigentoo.org/trac/linux-phc/
> 
> This seems to apply only to older cores. I have a Intel Core 2 Duo
> processor. Anybody knows if this is supported? i browsed the forums on
> gentoo and found that someone provided baz some info on the Core 2 Duo,
> but I don't know what is the current status.

its a bit more complicated..

normally the voltages are retrieved from the ACPI tables, so the kernel
dosn't know anything about the cpu..

the phc patch above has to calculate the voltage/frequency pair for each cpu
type.. so either you hack up the patch, its mainly simple to adjust the
voltage forumlar, or you wait until someone does it for you.. the patch is
planed so in some weeks it should work.

-- 
Florian Reitmeir