Linux and batterylife...

Are there certain distro that provide optimal battery life or equivilant battery life in comparison to say, windows mce?

I think i've read somewhere tha ubuntu's battery life isnt as good as windows.

Is there a distro made specificly for laptop users?

As you can see I'm new to the Linux world hah

 

I get about 4.5 hours on my Thinkpad with ubuntu. I think it has more to do with the hardware than the OS. Some laptops are better supported in Linux thatn others.

 

what is your avg battery life w/ windows?

I guess my initial question was in regards to a Dell e1405.

 

not a clue, i never use it

I would guess that its roughly the same. for a 15" notebook with a dedicated video card, 4.5 hours is about as much as i would expect to get.

I did use windows on this laptop for a couple weeks(got the lappy about 10 days before suse 10 came out, decided to hold out and do a fresh install of it), but that was with the standard battery, i bought a 9 cell later. with the 6cell the battery life was almost exactly the same in windows or linux (2.0-2.5 hours)

 

If you have a dual core you can choose to use a different kernel that is optimized for dual cores.

I know that for hyper threading P4 CPUs if you don't use the dual core (multi threading) kernel, the CPU overheats obviously consuming more power.

There are also kernels optimized for AMD CPUs

The linux world has something for everything

 

The battery life will be about the same, as you can undervolt the processor in linux like you do in windows when it is running on battery, etc. What WILL make a difference, is if you use an OS that chews the processor and gpu, for example Windows Vista.

 

I found an interesting presentation, linked here [PDF Warning!]
http://www.linux-pm.org/docs/pm-summit-0406-acpi.pdf

Battery life came up as an issue in the virtualization thread here
http://forum.notebookreview.com/showthread.php?t=66325
where there was some additional anecdotal debate on relative battery life between Windows and Linux.

The presentation is the first detailed comparison for battery life I've seen for Linux vs. Windows, albeit for only a single laptop, a Dell Inspiron 6400 (T2500). Roughly speaking, Windows achieves a battery life that is about 20% longer than Linux for most usage scenarios.

Of course, the linux numbers are still good but the question is what can be done in Linux to improve the situation...

 

Thanks for the link. Very interesting reading

 

The paper version of the presentation I linked to above is in the 2006 Ottawa Linux Symposium proceedings, the abstract of which is here
http://www.linuxsymposium.org/2006/view_abstract.php?content_key=140

If you want to look at the paper itself, open up the 2006 proceedings (volume 1, a big pdf) and the paper is on page 127. The results are the same as in the presentation, but there are a lot more details about the methodology, etc.

For those of us using Linux, one intereting note is that throttling (ACPI T states) is generally a bad idea for battery life compared to using the ACPI P states. LCD screen issues are explored a bit, but I didn't see anything on HDD spin-down issues (though they did compare 5400RPM vs 7200RPM)

 

Hey, what department are you in @ UTA?

 

I get about 5.5-7 hrs in Arch linux with my regular 6cell + 4cell ultrabay battery on my T41p.

Recently I foudn out that I can underclock and undervolt my gpu as well which gives me atleast another 40min.

 

Would you mind if share us how did you undervolt/clock in Linux? Did you do it on the fly or recompile the kernel?

 

Here's a guide:
http://gentoo-wiki.com/HOWTO_Undervolt_a_Pentium_M_CPU

 

Thanks, but it is still the P-M guide. What about GPU stuff? any battery life comparison before and after GPU twicking?

 

Whoop, sorry I must have misread gpu as cpu. Now, the only option I've found to undervolt the gpu seems to be using the ATI Powerplay included in the official ATI linux drivers. You can also lower the clock speeds witch rovclock.
http://forums.gentoo.org/viewtopic-t-343029-postdays-0-postorder-asc-highlight-rovclock-start-0.html
http://www.pyrocpu.com/index.php?page=phx&px=MzM=

 

Hum, these are worth to try on my V2000z ATI x200M.

Is there anything on Nivida side? Go 7200 or 6150? Any clue?