Power Management on Neo1973 - kernel 2.6.24

Alexandre Ghisoli alexandre.ghisoli at ycom.ch
Fri Jan 11 09:14:09 CET 2008

Le jeudi 10 janvier 2008 à 22:40 +0100, Tim Niemeyer a écrit :
> Today, i played a bit with power measurement and standby.
> It was very surprising, and the actual power was very different from time
> to time. Sometimes neo booted and did draw about 400mA in idle. Sometimes only
> 280mA.
> In Standby mode it was exacly the same, but most the time it tooks
> ~80-95mA. Sometimes only 65mA!
> One time the neo did draw only about 20mA! Don't know what was
> different: booted -> standby -> 20mA! I think this 20mA was drawn by the
> GSM.

Just to add on this topic, kernel 2.6.24 (tested -rc7) is really power
saving. On my laptop and, I cannot go under 9.7W while LCD
power on and laptop turned on.

With 2.6.24-rc7, I can goes down at 6.5W !

It seems that kernel has really nice power improvement ! And of course
HPET and dynamics ticks are required to wake up CPU less often.

And my tests showed the sound card eat 0.5W. The new AC97 path allow
standby when not used.


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