Re: Average power consumption in S3?

From: Martin Josefsson
Date: Wed Mar 09 2005 - 12:35:34 EST

On Wed, 2005-03-09 at 15:26 +0100, Moritz Muehlenhoff wrote:
> Hi,
> I'm using an IBM Thinkpad X31. With stock 2.6.11 and the additional
> radeontool to power-off the backlight in suspend, S3 works very well
> and reliable. During S3 I've measured a power consumption of 1400
> to 1500 mWh (using 512 megabytes of RAM). Is there still room for
> optimization? What's the typical amount of energy required for suspend-
> to-ram? From friends using iBooks with MacOS X I've heard that they
> left the notebook in suspend when leaving for a week and could still
> use it after return.

I also have an X31 and I noticed that the e1000 has Wake-On-Lan enabled
by default and the S3 code doesn't disable that (kind of defeats the
purpose :)
Disabling that will make the e1000 driver power down the chip during S3.

ethtool -s ethX wol d

I don't know if you have the e1000 or e100 in your machine, but I think
the e100 driver does the same.

I've had mine suspended for 2-3 days at most, actually havn't left it
alone for longer than that in S3 so I'm not really sure how much power
it consumes, but I'd say it's 1-2 percent of the total capacity per
hour, so somewhere below 1000mW.

I also use the standard radeontool to disable the backlight, I'll test
the version Matthew pointed out some day.


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