Why don't you do some testing and tell us ?
Actually, yeah, that's probably my best bet. I guess since I know the GTX 285 and 5850 are very similar in performance my bigger question was which scales better for games, SLI or Crossfire, which a whole other debate. I'm guessing the 5850 will do better, but then again it is also in a slightly "inferior" CPU setup. The results should be interesting.