Test on Ubuntu 10.04 64 bits to see the performance with a 1080p video, VirtualBox with WIndows 7 Ultimate, 720p video on Youtube, and most common effects of Compiz.
PC characteristics:
-Asus Crosshair IV Formula
-AMD Phenom II X4 965 @ 3.4 Ghz
-Sapphire Radeon HD 6850
-8 Gb RAM 1333 Mhz
-24" Monitor @ 1920x1200
