Battery life in Ubuntu

[lukee]

Hi, when I am using W7 I can get 4 - 5 hours of battery life with extended battery on my T43p. When I boot to Ubuntu 10.10, I am not able to get more than 2 - 2.5 hours of battery life altough I set Powersave profile and minimal intensity of LCD's backlight. Where could be the problem?

[jronald]

The only area I have seen Windoze excel at is battery life. uBuntu will not get the same life.

Ron

[ThinkRob]

Hi, when I am using W7 I can get 4 - 5 hours of battery life with extended battery on my T43p. When I boot to Ubuntu 10.10, I am not able to get more than 2 - 2.5 hours of battery life altough I set Powersave profile and minimal intensity of LCD's backlight. Where could be the problem?

My bet is that the GPU doesn't have the proper drivers installed, and as such isn't going in to power-saving mode. Did you install the restricted ATI drivers?

Other things to check/enable:

- WLAN power saving
- Bluetooth on/off
- hard disk spin-down/parking (I think Ubuntu has this preconfigured, but I can't remember)
- anything else that powertop recommends

The only area I have seen Windoze excel at is battery life. uBuntu will not get the same life.

With the exception of a few machines with an ATI GPU, that is most decidedly wrong. In fact, a number of machines can actually achieve better battery life under Linux than Windows, especially with recent kernels.

[lukee]

Hi ThinkRob. I am using an opensource ATI Radeon driver because ATI doesn't support Radeon X600 family anymore with the binary drivers. Bluetooth is off, WiFi is used gently.

[ThinkRob]

Hi ThinkRob. I am using an opensource ATI Radeon driver because ATI doesn't support Radeon X600 family anymore with the binary drivers. Bluetooth is off, WiFi is used gently.

Ah yes. AMD and their wonderful driver support. Yeah, if they dropped support for modern kernels, that might explain it. When I last ran Linux on my T43p the ATI driver still supported the GPU, and power-saving worked fine.

That said, I believe there are some power-saving features with the radeon module.

Also, have you run powertop and followed its advice?

[i-SnipeZ]

The open drivers are most likely the reason. I don't get better, but I do get equal battery life in Ubuntu compared to Windows on my machine, but, if the drivers you're using, especially for the video card, don't support power saving options, it's not a surprise your battery life is horrible.

[ThinkRob]

The open drivers are most likely the reason. I don't get better, but I do get equal battery life in Ubuntu compared to Windows on my machine, but, if the drivers you're using, especially for the video card, don't support power saving options, it's not a surprise your battery life is horrible.

FWIW, my T500 got better battery life under Linux than Windows when using the Intel GPU, and vice-versa when using the AMD one (even with AMD's proprietary Linux driver.) The difference wasn't significant either way, but it was consistent.

[comps]

There's an ongoing development of power-saving features in the radeon/radeonhd drivers. The basic framework was added in 2.6.35, though I failed to use it with that kernel. Use 2.6.36 - or better - the latest stable/rc kernel.

See ie. http://www.overclock.net/linux-unix/731 ... river.html - there are some useful hints for both UMS and KMS.

It won't probably be as good as the fglrx driver, but it's better than nothing.

[frankausmtank]

There's an ongoing development of power-saving features in the radeon/radeonhd drivers. The basic framework was added in 2.6.35, though I failed to use it with that kernel. Use 2.6.36 - or better - the latest stable/rc kernel.

See ie. http://www.overclock.net/linux-unix/731 ... river.html - there are some useful hints for both UMS and KMS.

It won't probably be as good as the fglrx driver, but it's better than nothing.

Now that's a nice hint, thanks. I made a desktop shortcut for

Code: Select all

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

to manually trigger the low setting without going to the command line. Refresh rates on glxgears in fullscreen mode dropped from ~60 fps to ~25, so there seems to be something happening (2.6.35 here). Didn't check for an improvement in battery life yet.