Re: Status of X86_P4_CLOCKMOD?

From: Andi Kleen
Date: Fri Feb 24 2006 - 23:40:35 EST


On Saturday 25 February 2006 02:57, Johannes Stezenbach wrote:
> On Thu, Feb 23, 2006, Dave Jones wrote:
> > On Thu, Feb 23, 2006 at 08:59:37PM +0100, Adrian Bunk wrote:
> > > And if the option is mostly useless, what is it good for?
> >
> > It's sometimes useful in cases where the target CPU doesn't have any better
> > option (Speedstep/Powernow). The big misconception is that it
> > somehow saves power & increases battery life. Not so.
> > All it does is 'not do work so often'. The upside of this is
> > that in some situations, we generate less heat this way.
>
> Doesn't less heat imply less power consumption?

Not in this case no.

> P4 clockmod certainly sucks compared to Speedstep,
> but IMHO it is still potentially useful for the average
> desktop PC user (at least those many who let their PCs
> run 24/7, but 90% idle and unused).

I don't think so no. The latencies make it unusable.

-Andi

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