[ltp] Battery drain in S3

[Bob Alexander]

Joachim Schrod wrote:
>>>>>>"NK" == Nathan Kurz <nate@verse.com> writes:
> 
> 
> NK> On Tue, Dec 07, 2004 at 07:50:59AM +0100, Bob Alexander wrote:
> 
>>>From the help I have received from this list and reading around I have 
>>>understood that:
>>>
>>>1) APM is much better when suspending in low battery drainage
> 
> 
> NK> I've read that many times too, and while I'm certain it was true
> NK> at some point for some hardware, I don't know that it is now. I
> NK> just did a little measuring on my X30 running 2.6.9 and ACPI S3
> NK> suspend-to-ram, and it seems to use abou 550 mW while sleeping. 
> NK> This is about 1.25 % of battery capacity per hour, and about what
> NK> I've seen people claim for APM sleep.
> 
> 1.24% per hour == 30% per day
> 
> Using APM and a 2.4 kernel, suspend-to-ram (equivalent to S3) eats
> roughly 10% battery power per day; both on my T21 and my T41.
> 
> Such information (30% battery drain per day in S3) kept me from
> migrating to 2.6, for now. (Suspend-to-RAM on lid-close is the most
> important function in power management that I need.) OTOH, Fionn
> Behrens reported in this thread about a drain of only 5-10% per day.
> 
> thinkwiki has no information on battery drain in S3. If you follow up
> with more experience, I compile it into information for the
> PowerManagement topic there.
> 
> Cheers,
> 	Joachim
> 
> --
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Joachim		     The most exciting phrase to hear in science, the
> Rödermark, Germany   one that heralds new discoveries, is not "Eureka!"
> <jschrod@acm.org>    (I found it!) but "That's funny..." [Isaac Asimov]

Joachim
first of all I wish you and yours an happy 2005.

I have done quite a few experiments with kernels and APM/ACPI on my T40 
and am in the middle of a large river :(

Under 2.6.9 with APM battery drain is quite good: around 0.9% of my high 
capacity battery per hour. The problem is that when I ran this test 
leaving the PC suspended to RAM overnight I quickly discovered that when 
left in suspend to RAM for periods longer than around 30 minutes the 
resume just hangs (while for shorter perdiods it resumes perfectly).

This is why I tried 2.6.10 but in this I have the opposite behaviour: 
the resume comes out perfectly even after protracted periods bu the 
drain is unacceptable at around 9% per hour !!! This is also 
strengthened by the fact that when suspending to RAM with ACPI the 
mouse, the CD in the bay and the network adapter all appear to stay on 
and the bottom of the TP is consequently quite warm.

I also tried 2.6.10-rc3-mm1 and the drain is a little better but still 
too high (6% hour) but for reasons I cannot understand X appears 
starting but the GDM screen aborts.

So I am not in good shape :(

Any ideas/suggestions ?

Take care,
Bob