This worked perfectly on my MSI P6N Diamond board with the Q6600 (B3 stepping). It didn't give me any additional headroom for my overclock, still stuck at 2.73ghz on that POS board. On a happy note, the same CPU runs at 3.13ghz on my Asus P5K Deluxe.

You do get a 2-3% performance boost by having the 1333mhz bus vs 1066mhz, according to the review here:
http://www.xbitlabs.com/articles/cpu...duo-e6850.html

They show the identically clocked 1333mhz and 1066mhz CPUs and the 1333mhz wins in every benchmark by 1-4%. I really can't explain why, I mean there's a bit more bandwidth there, but we're not talking anything earth-shattering. You'd be better off to overclock everything to 1333mhz and get the benefit of lower latency and more bandwidth with your overclocked memory than just running the higher FSB alone. I guess to each his/her own though.