Re: Centrino question

Martin Hermanowski
2004-05-23T21:54:31Z

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On Sun, May 23, 2004 at 05:33:04PM -0300, Dino Klein wrote:
> Windows will use throttling to save on battery, when you are using the Max
> Battery policy, and power is unplugged.
> Check the following link, where MS explains the policies in XP:
> http://www.microsoft.com/whdc/system/pnppwr/powermgmt/ProcPerfCtrl.mspx
>
>
> >From: Cyril Wattebled <neurowork-GANU6spQydw@public.gmane.org>
> >....
> >Yes, I have already asked around why this happends. Windows slows the
> >processor
> >down to 200 mhz when unplugged and down to 600 mhz when plugged. Windows
> >behaves just like linux with the AC power on but when on battery, it
> >manages
> >to slow it down to 200mhz. This allows the laptop to last more than on
> >linux
> >and also, the temperature of the overall laptop is cooler (which is really
> >more
> >confortable).
> >It seems that Windows is using some kind of clock modulation along with the
> >enhanced speedstep. I'm not sure about that but, I was told that it should
> >be
> >something like it. (cf cpufreq mailing list, thread called "Pentium M
> >minimum
> >clock modulation").

I just tried `echo 7 > throttling', and I noticed that the system is
quite underpowered at 75 MHz, so this seems to work. Byt it did not
change the power consumption. I am getting 3.5h at throttling = 0 and
the same at 4, but this seems quite ok with the 6 cell battery in the
t41p. I can get up to 4h when I turn off the hard disk.

I never tried the pre-installed windows, but I think that the advertised
runtime with this battery is about 4 hours.

Should I be able to reduce the power consumption by activating
throttling?

LLAP, Martin

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