On normal working with nothing opened,
compiz fires up to 50% CPU usage on my machine. Which is abnormal I think.
Is this a bug or is this behavior ok?
I am running Ubuntu 12.04 on Intel i5 processor
ATI 5400 mobility 512 MB Graphic card
Had the same problem. Compiz constantly at around 40% (AMD CPU, ATI 58xx, 12.04). Then i followed this post https://askubuntu.com/a/127310/26508 and CPU utilization dropped below 10%. Hope it helps.