Re: [dwm] [OT] frequency scaling and power consumption

On Sat, 09 May 2009, Preben Randhol wrote:
> On Sat, 9 May 2009 13:56:09 +0800
> bill lam <cbill.lam_AT_gmail.com> wrote:
>
> > Thanks all for confirmation. Since I only have a desktop, no
> > notebook/netbook ;-( it is somehow difficult to verify the
> > improvement. I now lock the cpu frequency to 1.1GHZ (half of the
> > original 2.1G).
>
> Why on earth do you want to do this to a desktop computer? It will have
> next to no effect on your power consumption. I mean you whole system
> will draw the main part of the power. Anyway, put the power saving so
> that the CPU scales with load. This makes more sense. And turn down
> the brightness on your monitor, that saves power too.

I got a wattage/current electricity meter to measure the actual power
consumption.

assuming power factor=1, unit in watts

                    BIOS LOCKED AT
........................... 1.1GHZ .......2.2GHZ
loading ~3% 53 55
mplayer/avi ~16% 66 70
./configure && make ~50% 69 83
full load >90% 75 93

It appears the saving is only a few watts for light to normal loading.

I use reverse video (white on black), the lcd use about 10 watts.

-- 
regards,
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