http://forum.beyond3d.com/showthread.php?t=50606
Crysis - Contact - Original Engine - High Settings : Min 17fps Max 116fps Average 53fps
Crysis - Contact - Warhead Engine - High Settings : Min 23 Max 127 Average 67fps
And Warheads version of 'high' ( Gamer ) enables more then effects then Crysis's 'high'
More performance coupled with more eye candy
Results from benchmarks may vary depending on your rig
Enjoy