My core is actually poor on my 8800GTS 512, some people do 850 with 1.4V on the stock cooler, it takes mine 1.5V to do that with 2300 shaders. To get above the clocks youre hitting now, you need to volt mod the card. You can get the core a bit higher, and the shaders much higher. Crysis loves high shader clocks. And make sure to mod the cards bios with a updated fan profile so it throttles at higher temps, and new TIM allways helps for a few C.
The Q9450 has been treating me well.
OP, get the cards yet?!