Well if I make fsx run on two cores the ground turns to mush. On four I get go 800 knots, sharp as a tack.
And the 8800GTS 512 is a fantastic card. It's cheap, power efficiant, and fast. There is no other card that comes close to the 8800GTS 512, others are to expensive, (and faster), or a fair bit slower. If I had to buy now the only card I'd get is the 8800GT 512 / 8800GTS 512 (G92).