I got 3,921 on 3dmark05. My stock speeds are 445/396. Very odd, I wonder why you only got 3,659. I'm running latest Omega drivers.
Initial overclocking of X1600 is not as good as I had hoped...I wonder if I did not make good contact with heat sink and GPU. I removed compound that was on there and replaced with AC5. Using powerstrip I get artifacting at 500 on core. I moved back to 490 and no artificating. 4,052 at 490/396. I have not upped memory yet.
I'm still very happy with performance.

I can't wait to load some games.

more later...