so your claiming a older mame version of KI or KI 2 will run better then the most current?
When talking about slower PCs, most people only take into consideration older games. Of course you can't really run newer games on a setup like that.
The classics run, and everything up to the early/mid nineties runs pretty good (I play Neo Geo perfect, Capcom fighters run great, but MK, of course, runs like crap).
I haven't tried Killer Instinct on my arcade, only my main computer. (Dual core 2ghz)
When you consider the fact that I can't run Donkey Kong on my arcade unless it's an older version, yes, MAME has got slower (new sound routines).