Ubuntu Unity Proves Very Slow To KDE, GNOME, Xfce, LXDE
KDE with suspended desktop effects on full-screen windows was the fastest for handling Prey.
The "KDE SC 4.9 - Suspended" scenario was also the fastest for Reaction Quake 3.
All of the desktops aside from the stock KDE 4.9 were much faster than Unity 6.4 with Compiz. GNOME Shell has been doing rather well with these tests.