Foxconn's Dual GeForce 7900GX2 1024MB adaptor sports a 500MHz core clock with 1.2GHz DDR3 memory support. These clocks are lower than the GeForce 7900GTX, which has a 650MHz core clock with 1.5GHz DDR3 memory. For those who are unaware, Foxconn is now a contender in on the video card market.You can check it out over here.
Like the GeForce 7800GTX Quad SLI adaptors, the 7900GX2 adaptors are really two 7900GTX adaptors with the PCIe lanes from one card physically routed via a bridge connector to the main card. A PCIe x48 bridge chip sits on both physical PCBs. 16 of those lanes are routed to the motherboard and the other 32 are spread between the GPUs.
Quad SLI cards are expected to retail for over $1,000. You'll need a SLI x16 motherboard and a heavy PSU too because these system can jump to 650W during heavy operation.