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#11
Hmmmm maybe, but nothing significantly to be completely honest.
RAM frequency don't really affect gaming performance.
I went from a 4GB Corsair XMS2 DDR2 @ 800Mhz kit to a 4GB Corsair XMS3 DDR3 @ 1333Mhz one a couple of months ago and saw 0 performance improvements in games whatsoever.
Although In your case, going from 400MHz to 800Mhz might make a difference... I don't know.
But you should definitely consider upgrading that RAM.