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Subject: Re: Question about cpufreq governors
From: Arjan van de Ven <arjan@infradead.org>
To: Jan Engelhardt <jengelh@computergmbh.de>
Cc: DervishD <lkml@dervishd.net>, Linux-kernel <linux-kernel@vger.kernel.org>
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References: <20070706205045.GA2778@DervishD>
	 <Pine.LNX.4.64.0707062353510.1536@fbirervta.pbzchgretzou.qr>
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Organization: Intel International BV
Date: Fri, 06 Jul 2007 15:50:29 -0700
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On Fri, 2007-07-06 at 23:54 +0200, Jan Engelhardt wrote:
> On Jul 6 2007 22:50, DervishD wrote:
> >
> >    What I want to know is if I can choose "ondemand" governor instead
> >of the recommended for AMD64, namely the "conservative" governor, since
> >I will be switching between those two frequencies. I haven't found any
> >information about my CPU regarding latency when switching between
> >frequencies, so I don't know if I will be gaining anything using the
> >"conservative" governor.
> >
> >    Which governor is better suited for a CPU with only two fid's,
> >"ondemand" or "conservative"?
> 
> Depends on what you want. ondemand instantly switches when there is
> something/nothing to do, while conservative uses a threshold (modeled upon
> latency).

for power saving, the ondemand behavior is better in general. However if
you have a cpu that switches frequency very slowly, you may be better to
not go as high quickly because going back down is then burning more
power than needed potentially...