I just explained this in another thread, but ill do it again lol
Alright well the E8400 is dual-core and the Q6600 is Quad-Core. Now in game performance the E8400 will beat the Q6600 in most games. But if you pit the E8400 against the Q6600 in a game or program thats optimized for 4 or more cores than the Q6600 will come out on top. The problem is most games are only coded for a max of 2 cores, and the E8400 has 2 cores that are clocked higher than 2 of the 4 that the Q6600 has. But when all four lower clocked cores are against the 2 higher clocked ones then the Q660 will win. Now both deliver awesome general performance (not games, ect.) the Q6600 will deliver better general performance. Also the Q6600 is more future proof because as newer games come out they are optimized for more cores, and as I covered in any 4 core optimized program the Q6600 comes out on top.
Uhh, I mean, Go look for yourself! yeah.. i fit in, thats right