The die shrink between Nahalem and Westmere did not produce any really significant performance gains, it only allowed higher core counts on LGA 1366, with the i7 975, 980x and 990x being hexacore chips, and allowed room on the die for integrated graphics on the Clarkdale CPUs on LGA 1156. The integrated graphics aren't going to do you any good for gaming, so that's not really an advantage for you. Even with the higher lithography, you're still better off with the 2 additional cores that the i7 860 offers. If you can't overclock, I would suggest maybe looking for the i7 870 or 880, which are clocked higher and would help performance in games.