they SHOULD be compatible, however i really wouldnt want to do that for a couple of reasons.
1. you cant us the 4x bandwidth
2. the graphics card will most likely be overpowered, thus all your games will be CPU limited and the card will be sitting around idle most of the time.
i tried a tnt2pro and a geforece2pro on my 386LX mobo, and could barely tell the difference between the two.
Need MUCH more chlorine in the gene pool i believe.