i5-3570k @ 4.2 performance

Is this processor good enough to run RPCS3 at a solid framerate? I'd like to play Demon's Souls, probably some JRPGs and eventually MGS4.

Anyone? Will this processor maintain a solid 30/60 in the majority of games?

There isn't a processor around that will give you solid performance in a majority of games. Some games run better then others.