hi ... im building new rig ..

intel quad 6600
mobo Asus P5N-D (SLI, 1394) - NF750i Chipset
OCZ NVIDIA SLI Ready DDR2 800 (2x1GB) with heatsink
MSI N8600GT 256mb DDR3
Cooler Master - Extreme Power Plus 460Watts

i want to know what the best setting for this mobo because when im running crysis , only get 25fps. is that normal.

rite now im using 4-4-4-15 auto setting for ram and 1.9v for da memory
my fsb run on 1333mhz and ram running on 800mhz

plz giv me any good advise for this thing
thank u