XFCE as a power saver

[mreq]

Have some of you noticed difference in power usage on a laptop? I am amazed at how light XFCE runs.

My laptop battery lifetime went to 4h from ~2.75h of full usage (wifi & work) on either Unity or Gnome shell. Also the temperature is ~5°C lower. Though I miss some things I liked on Gnome (mainly alt+tab switcher, the XFCE's one sucks ) I can say that I now officialy dig XFCE.

[neu5eeCh]

I use XFCE and have read rumors confirming what you say. Would be interesting to see some actual stats. Phoronix maybe?

[mreq]

never tried Phoronix, but:

The reason I switched from Gnome was gnome-shell constantly consuming ~15% CPU visible with `top`. Unity (compiz) was a bit better, but still ~12% CPU. With XFCE I rarely see any Also the wakeup stats in powertop tend to show there's a major difference.

[montag dp]

never tried Phoronix, but:

The reason I switched from Gnome was gnome-shell constantly consuming ~15% CPU visible with `top`. Unity (compiz) was a bit better, but still ~12% CPU. With XFCE I rarely see any Also the wakeup stats in powertop tend to show there's a major difference.

That's weird, you're saying the other desktops used that much cpu at idle? Doesn't seem right.

I've been using TLP for power management on my laptop, which has proven to work very well. It saves probably a couple watts most of the time, including at idle. I use KDE and get better battery life on Linux than on Windows 7.

http://linrunner.de/en/tlp/tlp.html

[kyalami321]

montag, the CPU usage might've gone up so drastically on the OP's machine when using Unity due to the increased graphics requirmeent. since we're talking about battery, the OP's machine is likely a laptop, likely with integrated graphics; hence the CPU usage, HDD activity likely increased as well, though this depends on available/installed RAM more so than video.

[montag dp]

montag, the CPU usage might've gone up so drastically on the OP's machine when using Unity due to the increased graphics requirmeent. since we're talking about battery, the OP's machine is likely a laptop, likely with integrated graphics; hence the CPU usage, HDD activity likely increased as well, though this depends on available/installed RAM more so than video.

But if he's talking about idle performance (which I'm not sure based on his post), I don't think it should matter, right? If you're not changing anything on the screen there shouldn't be much graphics requirement. I'm not totally sure if that's true, but on my laptop with integrated graphics running KDE, the CPU usage gets near 0 at idle.

[mreq]

Yes I've got an integrated Intel graphics. The CPU usage was ~15% when idle, which seemed like WAY too much. I've got 8gb ram. With XFCE it's fine ~0%.

[TOMBSTONEV2]

From my experience unity causes there to be a higher idle processor usage. I have intel integrated graphics as well and I have tried ubuntu 12.04, 12.10, and lubuntu 12.10. The processor was the same on ubuntu 0-2% on idle, lubuntu was 0-1% idle. Now I have debian, my processor stays mostly at 0% occaisional 1% on idle. 12 - 15% is really too high for any os on a computer. I would look at what is utilizing the processor.

[mreq]

I don't know what could be wrong. I observed, that when completely idle it's about ~3%, but when I do alt+tab to chrome and immediately alt+tab back, I see above 20%. On XFCE, it's 0% to 3% after alt-tab.

Could something with my Intel card be wrong?

petr@sova:~$ glxinfo | grep render
direct rendering: Yes
OpenGL renderer string: Mesa DRI Intel(R) Sandybridge Mobile 
    GL_NV_conditional_render, GL_ARB_ES2_compatibility,

[andrew.46]

Have a look at a decent installation of Fluxbox and you will start considering xfce a resource hog .