The 3dmark06 scores are fine, I highly doubt the motherboard in this as it is unlikely that it would slow you down playing games.
Crysis needs a strong cpu and a gpu to play smoothly, and also loves quad cores. Have you tried any other games or compared your setup with the 3dmark ORB? If you are into it, try overclocking the graphics card, and then the cpu, but only one at a time. See which makes your average fps increase more, to see what the biggest bottleneck is.