On the face of it, £470 for a graphics chip doesn't seem the best of deals. But what if that money bought not one but two chips? That's the question posed by nVidia's 7950 GX2 Extreme Edition and it calls for some serious thought.
In essence the GX2 consists of two GeForce 7900s working together in a manner almost identical to a typical SLI (scalable link interface) system. This makes for some rather juicy specifications, from the 48 pixel-shader processors and 512bit memory interface, to a full 1GB of DDR3 RAM.
Mind you, it's not all jaw-dropping. Despite XFX having seriously ramped up the clock speeds from nVidia's original design, they're still rather modest compared with the high-end single-chip cards. The core speed of 520MHz is 130MHz down on the 7900 GTX and Radeon X1900 XTX, while the memory clock falls 150MHz behind that of the GTX.
Boot up some games and the doubts evaporate. On Quake IV, for instance, the GX2 showed itself to be a good 5-7fps (frames per second) faster than the other high-end cards at 1,280x1,024. And the lead stretched to double figures as we moved up to 1,600x1,200 and beyond, with detail levels ratcheted to the full.
However, to get a consistent lead, you really need to be running your games at a minimum resolution of 1,600x1,200 and with such features as anisotropic filtering and anti-aliasing ramped up, too. Indeed, without such tough obstacles, the 7950 sometimes found itself being beaten by the X1900 XTX and 7900 GTX in such titles as Fear and Half-Life 2. And while games that thrive on SLI ought to produce some searing frame rates, you could find performance takes a hit with ones that don't.