For Blitz and Gauntlet Legends, you just need a lot of speed. It is pretty good with a 4Ghz Core2Duo. There is still a little slow down once in a while, but with that cpu, it is full speed most of the time. Probably 4.5 Ghz would clear up the rest of the slowdowns, but my chip won't overclock that far, so I can't test it. I just looked on Newegg, and the fastest c2d they have is 3.33 Ghz, so overclocking is mandatory. AMD chips won't cut it, and Core2 quad, extreme, and i7 do not give enough of a performance boost in MAME over a c2d (if any) to make it worth the money.