Comment 41 for bug 993397

Ok, reinstalled 12.04 and upgraded the Nvidia driver with xorg-edgers, vdpau is working again. But compiz is consumming a lot of cpu cycle even when idle. The high cpu usage is not observed in 12.10 so it appears to be a Compiz bug which is fixed in 12.10 but have not been backported to 12.04 yet. A work around is to uncheck sync to Vbank in both Nvidia settings and ccsm 's OpenGL tab then compiz's cpu usage becomes normal again.