First of all you'll get a slight performance hit for using a PCI-E 1.0 motherboard as opposed to a PCI-E 2.0 motherboard with two 16x lanes. On top of that your CPU is limiting your performance. Nvidia drivers do take advantage of multiple cores when running in SLi so upgrading to a newer quad or tripple core CPU would help you there. You should check the EVGA website to see if you can support newer AM3 CPUs with a BIOS update. If not then see if your board will at least support the phenom quad cores so you can go with something like a 9950 or a 9850 and overclock it. If your board does not accept that then you should look into overclocking your current CPU until you can upgrade your board and CPU.