[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Saving battery power



-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Mattia Dongili wrote:
> On Sun, Mar 11, 2007 at 10:50:35AM +0100, Thorsten Schmidt wrote:
>> Hello,
>>
>> Am Freitag, 9. März 2007 23:12 schrieb Mattia Dongili:
>>> On Fri, Mar 09, 2007 at 09:52:20PM +0100, Thorsten Schmidt wrote:
>>>> Am Freitag, 9. März 2007 21:41 schrieb Mike Hommey:
>>>>> On Fri, Mar 09, 2007 at 09:25:46PM +0100, Thorsten Schmidt
>>>> <meine_mailings@web.de> wrote:
>>>>>> Am Freitag, 9. März 2007 20:42 schrieb Mike Hommey:
>>>>>>> On Fri, Mar 09, 2007 at 08:32:21PM +0100, Thorsten Schmidt
>>>>>> <meine_mailings@web.de> wrote:
>>>>>>>> for some time I've been trying to reduce my laptop's power
>>>>>>>> consumption (while running on battery power) on my
>>>>>>>> Fujitsu-Siemens Lifebook C1320 with Debian etch.
>>>>>>>> - I echo powersave to
>>>>>>>> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor - I
>>>>>>>> installed laptop-mode in order to shut down my harddrive if it is
>>>>>>>> unused. - I don't use swap,  /tmp/ is a ramdisk-mount and
>>>>>>>> /var/tmp links to /tmp, (I've 1 GB RAM)
>>>>>>>> Thus my hd is barely used and my CPU reaches C3.
>>>>>>>>
>>>>>>>> But for some reason, Windows is more efficient in power saving.
>>>>>>>> (3,5h vs. 4,5h battery life while surfing wireless).
>>>>>>>> Is there anything else I can do to save battery power?
>>>>>>> Basically, no, except waiting for Linux ACPI support to get better.
>>>> Is this about to happen soon?
>>>> Would switching from vanilla (2.6.20.1) to -mm be an option?
>>> probably using CONFIG_NO_HZ=y (yes, available in -mm), but you'll hardly
>>> get one more hour.
>>> Give it a shot.
>> Thanks, I'll do so. - the kernel is compiling now.
>> Btw. back in good old 2.4 times, I recently patched ACPI to make it useable.
>> Is patching ACPI still a good idea?
>
> no. Moreover if you switch to -mm you'll get the acpi test branch which
> is ahead of plain 2.6 kernels anyway.
>
> To save some more power in linux you may also want to try unloading
> usb modules.

If your processor supports it, you could try undervolting, I got about
15 more minutes out of it, but the main gain, is that temperature
stays remains a lot lower, and so the fan also works less, which saves
noise, and some energy too. Here is where I looked at:
http://www.thinkwiki.org/wiki/Pentium_M_undervolting_and_underclocking
.  The stress testing part is very important ihmo, and I have to tell
you that i am not 100% sure it is absolutely safe for the system,
although i didn't have any problems.


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFF9HLpmtnb6d8/tK8RAqQtAJoClOWsW1hX1vS7CthrwnsNrCioqgCeNhpd
SaxmXzWxHUD3735DZgWBfgA=
=PIqx
-----END PGP SIGNATURE-----


Reply to: