The GeForce 7950 GX2 has just about the same size as the 7900 GTX. While the cooler of the GeForce 7900 GTX is a two slot solution, the GeForce 7950 GX2 uses two copper coolers. The back of the cards shows the much smaller number of components on the 7950 GX2 compared to the 7900 GTX.
The front of the 7950 GX2 has nothing out of the ordinary. The DVI connectors are placed on the top PCB so the bottom has the space needed for the air vent. The rear of the card shows one PCIe power connector to power the card. It draws around 143W of power according to NVIDIA. That is not much more than one X1900 XTX, but the performance per Watt ratio is much better with the NVIDIA part.
The bottom of the card has one PCIe x16 port, while the top has one SLI connector, located in the middle of the card. The previous 7900 GX2 had two SLI connectors, one on each PCB, located toward the front of the card. The 7950 GX2 is interconnected in-between the cards now.