I think your SDRAM memory is probably hurting you. I'm running a TI4400 at only 300/600 and I get a higher score, but I have an AXP1700 and DDR. But your CPU is at 1.7ghz which even for a Celeron is pretty respectable, so I think your memory bandwidth is more to blame. And since you've already clocked the hell out of your TI4400, your best bet is to up the FSB on your CPU like ricercar suggested. You can also turn off AA and AF in the Nvidia control panel, and set quality to "best performance."