As I've only got back into PC gaming fairly recently I have alot of older titles that I'm working my way through (just finished Bioshock&Bioshock 2- both were awesome) so when the time comes to play more bang up to date titles I will probably upgrade my video card. Would my q6600 @3.77ghz (yes i managed to get a little bit more out of it) significantly push one of the HD5xxx series cards enough? I'm thinking only a HD5870 or HD5890 would be a significant upgrade from my GTX 275, or would an overclocked HD5850 still wipe the floor with my 275?