Just installed Ubuntu 13.10 and I am seeing higher CPU usage than expected

Question

I recently installed the latest version of Ubuntu. It runs great but there is one problem. Very high CPU loads. When I have chrome open, the computer is commonly running at about 50% load. When streaming videos, the CPU can hike up to 100% mark. The highest CPU users according to the top command are Xorg and compiz, which I know are UI apps. Chrome only takes around 10% usually and the rest is the UI.

What can I do to fix this? I followed the High CPU Troubleshooting Page on Ubuntu website but it didn't help. GPU is working fine, etc. I have an A10 3600M CPU. Thanks for the help.

Answer 1

Technically, xorg is the windowing system, and compiz is a layer ontop of the server which allows for 3D effects.

The high CPU usage is likely indicative of software rendering instead of hardware rendering.

As mentioned in this question, you can run /usr/lib/nux/unity_support_test -p to see if software rendering is being used. If so, you'll see something like:

Not software rendered:    no

I'm not familiar enough with where the AMD APU support is these days with regards to 3D drivers, but I'd check the additional drivers and see if there's any updates for fglrx or fglrx-updates, which should then enable hardware rendering, and reduce the CPU load.

If you want more of a boost, disabling some of the visual effects could help. CCSM can help with that:

sudo apt-get install compizconfig-settings-manager compiz-plugins-extra

After installing, you can just search for CCSM, and that'll let you disable some of the visual effects, which may help you get performance back.