Well, the processor and RAM might be a bit of a bottleneck, as well as the PCI slot, the video card notwithstanding. Honestly I'd recommend waiting a while until PCI Express comes out, saving your money until then. Then buy a whole new system. With the new PCI Express, AGP will become obsolete. Until then, if you really need a replacement, go with what one of these fellas said. I'd also check www.pricewatch.com as well as www.newegg.com. Well...that's about all I have to say. Hope it helped!