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Date: Mon, 3 Feb 2003 13:14:56 -0600
From: Matt Reppert <arashi@arashi.yi.org>
To: Valdis.Kletnieks@vt.edu
Cc: linux-kernel@vger.kernel.org
Subject: Re: CPU throttling??
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On Mon, 03 Feb 2003 13:57:17 -0500
Valdis.Kletnieks@vt.edu wrote:

> On Mon, 03 Feb 2003 17:13:02 GMT, John Bradford said:
> 
> > Incidently, Linux has always halted the processor, rather than spun in
> > an idle loop, which saves power.
> 
> It's conceivable that a CPU halted at 1.2Gz takes less power than one
> at 1.6Gz - anybody have any actual data on this?  Alternately phrased,
> does CPU throttling save power over and above what the halt does?

Yes. I have a powerpc laptop that runs at 700 MHz. If I throttle the CPU clock
speed down to 400 MHz and change nothing else the battery has noticeably longer
life; since it's running slower, it takes less power when it's active (not
halted).

Matt
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