Well,it\'s not a secret that XBox outperforms the poor flawed and inefficient PS2...but damn...it blows away even a 1.4Ghz AMD Athlon with an ATI Radeon 8500 graphics accelerator!!!
http://www.beyond3d.com/forum/viewtopic.php?t=1915Here\'s a translation of the performance table from the paper :
                Basketball player-----------------Bunny 
Platform--------Gouraud      Lit          Skinned        Gouraud 
PS2       17.0 / 22.6  10.9 / 14.7   8.5 / 11.5   25.2 / 31.8 
XBox      47.2 / 91.4  22.4 / 43.4  14.2 / 30.3   63.9 / 93.8 
NGC       18.7 / NA    10.3 / NA     7.2 / NA     NA   / NA 
PC        24.1 / 46.1  15.9 / 20.9   5.1 / 10.9   26.3 / 36.2 
and consider that 
the library was originally developed for the PS2, and they only spent "3 man months" porting it to Xbox, so you would expect the PS2 version to be more highly tuned than the Xbox version. But even so, the Xbox seems to be significantly faster on all benchmarks than the PS2.