[ltp] X200 Battery Life

[n0rdik0]

Henrique de Moraes Holschuh-2 wrote:
> 
> On Thu, 30 Oct 2008, Tino Keitel wrote:
>> On Wed, Oct 29, 2008 at 23:40:15 -0200, Henrique de Moraes Holschuh
>> wrote:
>> [...]
>> > Yeah, PCIe power saving + aggressive AHCI sata link power saving
>> > could be it...
>> 
>> What is "aggressive"? Something more than available in
>> link_power_management_policy? I once saw SCSI power management patches
> 
> link_power_management_policy set to its highest savings mode.
> 
>> flying around on LKML, which also had the aim to disable a SATA link
>> when the hard disk is spun down IIRC. Maybe you are referring to this.
> 
> No, but that sounds like something Lenovo is likely doing, yes.
> 
> -- 
>   "One disk to rule them all, One disk to find them. One disk to bring
>   them all and in the darkness grind them. In the Land of Redmond
>   where the shadows lie." -- The Silicon Valley Tarot
>   Henrique Holschuh
> -- 
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
> 
> 
Excuse me for replying for a pretty old message, but it seems to be more
appropiate than posting a new thread. If I'm wrong, feel free to yell at me
;)

I'm going to travel for christmas, I will be more than 24h without power
sockets and I'm trying to get the most out of my 9cell X200s battery. I've
been running some tests lately for minimum power consumption on Vista with
the Lenovo tools and on Linux with powertop. I will be reading documentation
and writing some C or PHP code in pretty dark environments, so the absoulte
minimum is almost realistic for me.
- On Vista, without spinning down the disk (Vista generates disk activity
every few seconds) the minimum power is around 5.3W, averaging under 6W for
an exact 3h period (the screen saver kicked in sucking more power). The
battery went down 17.8Wh in this time.
- On Linux, with every powersaving feature I could think of, the minimum is
7.1W, averaging 7.4W for a several hour period. This includes: minimum
backlight, cpufreq ondemand, laptop-mode, no radios, HD spun down,
hda_intel, pcie and sata powersave modes, usb autosuspend, fan off, kde3
environment with less than 10 wakeups/s. When the disk spins up, it goes
near 8W. Once (and only once) I managed to get it down to 6.2W by messing
with xorg.conf and setting 8bit depth (256 colors), but after restarting
couldn't reproduce the results. Anyway, even that is 1W+ more than Vista.
After these results, I have some questions.
- Is there any obvious thing I'm missing?
- Unloading ethernet and/or usb modules doesn't make any difference. Should
it?
- The hardware kill switch sometimes actually _rises_ the power drain for
0.1W (not much, really, but bizarre anyway) compared to wlan0 powersave mode
5. How can this be possible? Is it fixable somehow?
- What on earth is Lenovo doing on Windows to make such a big difference?
With disks spinning it's 8 - 5.3 = 2.7 Watts!! Almost 50% more on linux!! Is
there any way to ask them for help with this? Is there any way for me to
help figure it out?
Meanwhile, I will use Vista in my offline trip, as it gives me 3-4 hours
more battery life.
-- 
View this message in context: http://www.nabble.com/X200-Battery-Life-tp20188937p21085328.html
Sent from the Linux Thinkpad mailing list archive at Nabble.com.