Tom's Hardware Guide reports new motherboards with PCI Express x32 have some interesting possibilities such as Quad GPU SLI with Asus new Extreme GeForce 7800 GT Dual!
This monster of a graphics chip sports two 7800 GT chips running in parallel. We'd like to note a few things that are special about this card. First, only 2000 samples of this my-card-is-faster-than-your-card graphics board exist, worldwide. Second, the THG lab received two of them. Third, although the cards lack the usual SLI connectors, two of these monsters can nonetheless be combined via SLI. That means we can now achieve Quad SLI with four GeForce 7800 GT chips and a total of 1 GB of video memory.