I don't know but your 3dmark01 score seems pretty low for its speeds, should be much higher than that.
I'm getting 35800 marks with my 146 @ 3.2Ghz (using 166 divider for memory), X800GTO @ X800XT (581/601).
http://service.futuremark.com/compare?2k1=8799497
Your cpu runs 300Mhz higher than mine. Your card clocks are not bad for an unmodded card.
For example, when I had my X850XT, my best score was 33358 marks with a Winnie at 2766Mhz, card at 615/630.
http://service.futuremark.com/compare?2k1=8441296
I don't understand why you only have 1400 marks more with 750Mhz more cpu speed, 1MB cache also plays a role.