Another downloadable benchmark that's freely available is the Crysis Warhead Benchmark Tool
The average frame rate in Crysis Warhead under DX9 was over 60 fps at the first three results. The frame rate dropped to 47 fps at 1920x1200 w/4x antialiasing and at 2560x1600 with no aa, the average fell to 39 fps.
As expected, be prepared for a drop in performance under DirectX 10, which offers graphics improvements.
These results are from the ambush level with the Gamer setting under DirectX 9 and 10. ambush has a number of special effects like fire, smoke, explosions, particles, ragdoll physics, water, etc.
Gamer Setting - DX9 vs. DX10
Extreme Setting - DX10