I have a pretty high end PC, too. Windows 7 64 bit on a GTS8800 320MB card (DX10 compatible) and 4GB RAM. E6600 processor.
No offense but that is very far from high end.
I score around 3,000 on high and almost 5,000 on low. My specs are Core 2 Duo 3.0GHz, 4GB DDR2 RAM, and a ATI HD 4870 512MB. But this computer is pretty old now and I'll end up upgrading towards the end of the year.
"... and so I close, realizing that perhaps the ending has not yet been written."