overclocking an e6400 w/p965 platinum

[ncr7002]

This is probably a really dumb question, but I have a intel e6400 cpu on a p965 platinum msi motherboard with 4x 1gb sticks of ocz 667mhz ram and I was under the impression that at stock speeds, the fsb was running at 266mhz, which in turn meant the ram was running at 533mhz... although the bios says 667mhz.

If I raise the fsb speed then the ram speed raises as well, so for a 300mhz fsb I get 750mhz on the ram.

I thought I could up the fsb to 333mhz while leaving the ram at 667mhz. Am I completely off ? or is it because of my motherboard ?

I noticed the same behavior with an e8400 and 800mhz ram on a different motherboard, what am I missing here ?

I'd really appreciate any help, thanks.