In the mame options, I have tons of options: triple buffering, Direct Draw, Direct 3d, GDI I think it was called. They more or less all look the same. Are certain settings better than others? I'm not worried about the best graphics, just best performance.
My compy is a P4 2.8 with 1.5 gigs of sd ram. It won't run MK4 very well and other games that I think it should.