Guys, >No it only uses 3dnow1 instructions, so you can run everything on a K6-2 >if you want to (I do). The only usefull thing from 3dnow2 that I have >found is the SSE compliant prefetching. FYI: I seemed to get better performance using the 3DNow! prefetch than the SSE prefetch. Seemed to be mainly from using the prefetchw . . . Cheers, Clint