Last month, NVIDIA gave us the chance to have a look at its first implementation of Quad SLI, using a pair of GeForce 7900 GX2s. To cut a long story short, we had a slew of issues across a selection of top-selling games. NVIDIA itself has admitted that making four GPUs work together in tandem is no easy task. The company claims that creating SLI profiles for two GPUs is like riding a bike; creating Quad SLI profiles is a different kettle of fish all together.
On Monday, NVIDIA announced its GeForce 7950 GX2, marketing it as the fastest single card solution available on the market. Although NVIDIA classes GeForce 7950 GX2 as a single card, it actually has a pair of G71 graphics processing units on a pair of PCBs connected with a 48 lane PCI-Express switch. These have the same specifications as the pair of G71s on GeForce 7900 GX2, as far as sharing the same clock speeds.
This means that the two GPUs are clocked at 500MHz, with the vertex clock running at the same speed. Each GPU has access to a 512MB frame buffer clocked at 1200MHz DDR via a 256-bit memory interface. Despite these similarities, there are many differences between GeForce 7900 GX2 and GeForce 7950 GX2; we will come to these shortly.
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Physically, the card is massively smaller than the GeForce 7900 GX2 - the GeForce 7950 GX2 is the same length as both the GeForce 7900 GTX and also the Radeon X1900XTX. Obviously, this is a good thing, as it means that a single card, or a pair of GeForce 7950 GX2's operating in Quad SLI will fit in a standard ATX chassis. There is no longer a requirement for a large case in order to accomodate the length of the video card PCB, as it is a reasonably standard sized high end video card.
We say that because both ATI and NVIDIA have chosen to cool their high end video cards with dual slot coolers. The GeForce 7950 GX2 is a little different in that respect, because it uses a single slot cooler. That doesn't make it a single slot video card though, as there are two PCBs connected together, each with a G71 GPU, a 512MB frame buffer and a single slot cooler. NVIDIA has continued the tradition of relative silence on its flagship video cards, as the GeForce 7950 GX2 whispers along without causing headaches.