Re: Thinkpad X60s power usage on battery - Windows/Linux comparison

["Karthik Gopalakrishnan" <karthik.g.krishnan@gmail.com>]

What sort of a Graphics Accelerator does the system have. I faced a
similar problem on my Laptop & I narrowed down the issue to a bad
driver for my NVidia Graphics card. Once I fixed that, the battery
life on Linux matched up to that on Windows XP.

Regards,
Karthik

On Mon, Aug 18, 2008 at 6:54 PM, Vedran Rodic <vrodic@gmail.com> wrote:
> I've decided to write up something that I've been aware of for some time,
> but that didn't really bother me that much, since I've been waiting for the
> situation to improve quietly.
>
> The basic observation is: My trusty X60s uses less power when on battery
> on Windows than on Linux.
>
> This situation hasn't changed significantly despite the appearance of powertop
> to trim the number of processor wakeups per second thus enabling the
> processor to stay in deep sleep states for longer time and improvements in
> the Xorg intel video driver.
>
> I get arround 3.3 wakeups per second minimally when
> my Xorg/KDE is not active, with laptop using 9.1 W (as reported by
> powertop). When Xorg/KDE is running, with one konsole to monitor usage with
> powertop, I get arround 13 wakeups per second and power usage of 9.4 W. All
> the measurements are done with LCD brightness on the lowest level, wireless
> interfaces disabled, and all power saving features that powertop can detect
> enabled. Processor is in C3 state 99.9% of the time. I tried removing
> various driver modules that I didn't use at the time (irda, pcmcia,
> ethernet, sound), but no change.
>
> Windows power monitoring tool from Lenovo reports power usage of 6.5 W under
> the same LCD brightness level and with wireless disabled.
>
> This was tested under Linux 2.6.26-rc8 (some git level after the rc8
> release). Older
> versions of the kernel didn't show any statistically significant
> differences. powertop
> is version 1.10, and the software used under Windows XP
> is Lenovo ThinkVantage Power Manager.
>
> Since I doubt that Windows XP has less wakeups per second than my
> Linux setup, I guess
> there are still a couple of IBM specific power saving
> registers/controls that can be
> tweaked so that the laptop uses less power. Does anybody have any idea
> on what would that
> be? Any friendly contacts at lenovo?
>
> Thanks
> Vedran Rodic
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