Not too long ago, manufacturers such as Gigabyte and Asus made graphics card that took two nVidia chips and put them on to one card. My personal feeling on these is that they were pretty pointless as though you still needed an SLI motherboard you could only use one at a time, yet they cost the same as buying two cards. In the case of the Gigabyte, you even had to use a specific motherboard too.
So when nVidia launched the GeForce 7950 GX2, I was instantly concerned as to its application.
As you can see from the image above, this card is pretty much two PCBs bolted to together to make a single card. It uses one PCI-E slot and needs only a single power connector.
Above, you can see what the card looks like when pulled apart. There's a small connecting PCB that bridges the two 'cards' together. Each PCB has a GeForce 7900 GT core, running at 500MHz instead of 450MHz, but with the slightly slower running memory of 600MHz instead of 660MHz. The memory modules are the same 1.4ns Samsung modules, which are in theory rated to 715MHz. So one has to question the motive of underclocking these by 115MHz (or 230MHz when taking DDR in to account).
What first struck me about this card is how amazingly quiet it is. While I was comparing it to two 7900 GTs, the difference was astonishing. Despite this reduction in both noise and air flow, the temperature of the card seemed fine. When overclocking, it did get a little on the hot side, but I'd sooner hold off the clock speeds a little to save myself a noise related headache.