SKYSTAR u said that L3 cache gives higher fps. But the fact is L2 cache is much much more faster than L3 cache. So theoritically Q9550 with huge 12MB L2 cache should give more fps than L3. But there r other things that should come in concidaration like, i3, i5, i7 processors access ram directly and use QPI Path but the Quad cores don't thus make them faster.
As far as i know an Q9550 @ 4.0GHz is almost equevalant to i7 965 @ stock. But Sandy Bridge I7 r much more faster @ gaming as they have integrated Graphics. I just know these things from other foroums. I don't know exactly as i don't have any of these CPUs. Make me correct if i'm wrong.