Are you sure thats the right model number? I cant find it anywhere.
Also, is it just a plain old 6800, or a GS, GT etc? If its just a 6800, i would reccomend a 6600GT, its better.
BTW, the 6800 is on AGP too, so if you dont have a PCI-e slot, then you may have an AGP. Best thing to do would be open up your computer, and take a photo of the motherboard. Then we can tell you what you have.
