[ltp] what to use to save battery

Jiang Qian linux-thinkpad@linux-thinkpad.org
Wed, 6 Sep 2006 19:25:51 -0400


On Tue, Sep 05, 2006 at 03:34:49PM -0400, Andrew Barr wrote:
> On Tue, 2006-09-05 at 20:11 +0200, Florian Manschwetus wrote:
> > Andrew Barr wrote:
> > > Don't forget that having active USB devices prevents CPU powersaving.
> > no problem here (t60) and for cpu throttling forget userspace deamons 
> > just use ondemand or powersave governor of kernel powermanagement.
> 
> If your USB bus is active, it prevents the processor from leaving C1,
> which causes higher power consumption. Use a USB mouse or memory stick
> and watch /proc/acpi/processor/CPU[0,1]/power. This is why people
> recommend turning off Bluetooth and the fingerprint reader (USB devices)
> to save power.
Hi Andrew:
Could you be more specific on how I can turn off the fingerprint reader?  
I'd like to be able to turn it off when I'm on battery but turn it back 
on when on AC. Thanks.
Jiang
> 
> Andrew
> -- 
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