When buying GeForce card be sure you buy a retail version from a good manufacturer. There's lots of differencies between different cards in memory speeds and quality of components. Looks like Hercules/Guillemot and Leadtek cards are made of good parts thus giving better picture quality than some "NoName" cards.
My Prophet2MX came with Hyundai's 5,5ns mem (TC-55) and after I added a fan in it I oc'd it to core220/memory230 and best 3D-mark results were about 5800-5900 with P3-700 oc'd to 933, Dx7a and Nvidia's 6.34 reference drivers.