Arch Linux

Mihasi

Member

Registered: 2010-07-24

Posts: 10

Battery life: is it worth it?

Hello, everyone! It's been a while, but Arch has pulled me back in and I hope I'm here to stay. A couple of days ago I had an small operation that requires me to stay at home and high on pain medication, so I figured reinstalling Arch on my laptop would be a great way to pass that time. (The pain meds might have something to do with that...) You see, I've bought my current laptop on a student's budget and though it works fine, I have one gripe with it: the terrible battery life. While my sister can work on her Macbook the entire day without recharging, my Asus K52je won't last 2h without recharching. I decided to try setting up a dual boot with Arch again to see if it could give me some extra laptop time on the train or in the couch. I read https://wiki.archlinux.org/index.php/Laptop and installed cpufrequtils and laptop-mode-tools (among others), but to no avail. In Gnome 3 I only get about 1h30m, in LXDE I get 1h50m out of it.

I haven't gone over all the options yet and I wouldn't mind spending some more time on configuring power management if it could extend the battery life with 30 minutes or more. However, I don't feel like wasting another day finetuning configuration files for 5 or 10 minutes extra, so my question to you is: is it worth it? Is there a way for me to significantly improve the battery life of this laptop in Arch without sacrificing usability? On a side note, I do not NEED the extra battery time, it's just a hobby project. If I don't have a chance of getting any real results, I'd rather find another project.

litemotiv

Forum Fellow

Registered: 2008-08-01

Posts: 5,026

Re: Battery life: is it worth it?

This is not an Arch Discussion, moving to Newbie Corner.

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ethail

Member

From: Spain

Registered: 2011-02-10

Posts: 225

Re: Battery life: is it worth it?

pcie_aspm=force as kernel argument might help in order to force the kernel to use power management in devices that bios reports as don't capable of that but they are.

http://lwn.net/Articles/449448/

using cpufreq in order to manage processor frequency and some other tool to manage backlight levels of the screen could help you.

What kind of graphic card does your laptop have? nvidia ones had bad power management with one driver, ie. IIRC the nvidia driver (or was it with the nouveau ?). Information about card and model will make easier for people to help you in this subject

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Mihasi

Member

Registered: 2010-07-24

Posts: 10

Re: Battery life: is it worth it?

Thanks for the quick reply! I'm already using cpufreq to manage cpu frequencies (using the powersave governer when on battery) and laptop-mode-tools for the backlight (backlight is half of the maximum value when on battery, I could probably decrease this some more). I'll try the ASPM workaround, though.

The graphics card is an ATI Mobility Radeon HD 5470 (512 MB RAM) and I'm using the open-source ATI driver, xf86-video-ati. Sorry for posting in the wrong forum, by the way.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,785

Re: Battery life: is it worth it?

I assert that it is worth it. 
Battery life = Power. 
Power * time = Energy
Energy = {Dollars, Yen, Euro, Pound}. 
Power = how fast we convert organized energy sources into waste heat. 

Heat kills equipment.
Energy costs money.

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iTwenty

Member

From: India

Registered: 2010-10-24

Posts: 63

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Re: Battery life: is it worth it?

I have the same card as you have, only the 1GB version. The open source drivers give me hardly an 2 hours battery life while the catalyst drivers can easily manage 3+ hours. So you might wanna try that.

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Army

Member

Registered: 2007-12-07

Posts: 1,784

Re: Battery life: is it worth it?

If you have an Intel cpu, you could use phc-intel from the AUR, for AMD cpus there's phc-k8. Helps a lot! (although it's still dangerous, so use with care)
edit:
You also could execute

echo "low" > /sys/class/drm/card0/device/power_profile

for the opensource driver to make the card consume less power.
Last but not least, there's rovclock.
Example:

rovclock -c 200 -m 100

I don't know how much those two lines really change, but especially the first one is 100% safe.

Last edited by Army (2011-08-06 18:17:27)

Shark

Member

From: /dev/zero

Registered: 2011-02-28

Posts: 686

Re: Battery life: is it worth it?

I have ASUS K50IJ laptop. I have it for about 2 years now and i have never managed to get the battery working for more than 2,5 hours on Linux (i never installed Windows on it). CPU frequency scaling is not supported (i can't load the modules), pcie_aspm=force doesn't do anything, laptop-mode is enabled - in my case i surrendered in low-battery destiny

Last edited by Shark (2011-08-06 18:38:16)

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Mihasi

Member

Registered: 2010-07-24

Posts: 10

Re: Battery life: is it worth it?

I have the same card as you have, only the 1GB version. The open source drivers give me hardly an 2 hours battery life while the catalyst drivers can easily manage 3+ hours. So you might wanna try that.

Last time I used Arch I used the Catalyst drivers and it didn't seem to make a difference at all. I'm also surprised at how easy it is to set up dual monitors with the open source drivers: just plugging in the external monitor and that's it, so I'll stay with the open source drivers out of pure laziness.

If you have an Intel cpu, you could use phc-intel from the AUR, for AMD cpus there's phc-k8. Helps a lot!

Last but not least, there's rovclock.

I'm reluctant to try undervolting for several reasons. First of all, I have an intel i3 processor, which is apparently currently unsupported by phc-intel. I tried rovclock, but it doens't seem to detect the card right. Secondly, I used to undervolt the CPU of my previous laptop and it didn't seem to do much for the battery back then.

echo "low" > /sys/class/drm/card0/device/power_profile

This was an excellent idea, it's the first thing that made a big impact! I'm testing it right now, but when I executed this command the estimated battery time went from 1h39 minutes to 2h02m. Is there a way to make this happen automatically when the laptop is running on battery?

I have ASUS K50IJ laptop. I have it for about 2 years now and i have never managed to get the battery working for more than 2,5 hours on Linux

Still better than mine, which is only half a year old.

George

Member

Registered: 2011-05-11

Posts: 165

Re: Battery life: is it worth it?

Mihasi;
Have you every used powertop? it will give you lots of suggestions for improving battery life.

Mihasi

Member

Registered: 2010-07-24

Posts: 10

Re: Battery life: is it worth it?

Mihasi;
Have you every used powertop? it will give you lots of suggestions for improving battery life.

I have used it before, but I forgot about it. Thanks for the suggestion, I'll try it again.