Re: a question about p4_clockmod module on Xeon quad coreprocessors

From: Dave Jones
Date: Thu Jan 29 2009 - 12:09:20 EST


On Thu, Jan 29, 2009 at 08:32:41AM -0800, Xiaoning Ding wrote:

> > > Thanks for the correction.
> > > My experiments need to reduce CPU speed. However, I
> > can only reduce the speed by about 30% (from 2.67GHz to
> > 2GHz) with ACPI. That is not enough for the experiments.
> >
> > The ACPI P-states are nearly always correct, so you
> > won't be
> > able to go below 2GHz on this system.
>
> That's true for changing P-States with ACPI. But I can still get slower speed with clock modulation, right?

Clock modulation will lower the performance, but the clock speed
will remain constant.

Dave

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