Just been on my every-so-often visit to the modeler board and I noticed that they posted ballpark numbers as the sort off PC youll be needing for full speed.
Apparenty the less complex stuff like GA2 and spidey youll get away with a 500-550 but it goes up considerably when you get to the beefy games with Outrunnners at 850 and Rad Mobile being 1ghz+.
Pretty hefty, but not surprising considering the hardware.