High expectations are a self-inflicted, but nonetheless serious, problem for both ATi and Nvidia. In early 2004, for instance, the two goliaths of PC graphics unleashed a pair of new video cards, the Radeon X800 and GeForce 6800, which offered performance that annihilated every board that had come before them.

Fast-forward to the launch of Nvidia’s new GeForce 7800 GTX in June this year, where we found ourselves a little disappointed. Sure, the 7800 GTX became the undisputed world heavyweight champion of PC graphics, but it didn’t destroy the previous generation of cards in the way the GeForce 6800 and Radeon X800 had managed. Similarly, the arrival a few months ago of ATi’s competing card, the Radeon X1800 XT, made that card’s excellent rendering performance seem really rather ordinary.

In that context, what should you make of Nvidia’s new 512MB revision of the GeForce 7800 GTX? First, it’s important to note that it offers much more than just an additional 256MB of video memory. The 425MHz GPU core and 1.2GHz memory clock speeds of its predecessor have been boosted significantly, to 550MHz and 1.7GHz respectively. Consequently, the 512MB flavour of the 7800 GTX has become a big, bad dual-slot beast of a card, with perhaps the largest fan yet seen on a reference video board design. Architecturally, however, no changes have been made: it’s essentially the same 110nm chip with 24 pixel pipelines, eight vertex-processing units and 32-bit precision, Shader Model 3 hardware as before.

How does it perform? Its results are around 30 per cent faster than the 256MB 7800 GTX – making it the fastest video card in the world. In most 3D engines, it’s notably quicker than ATi’s Radeon X1800 XT, and the 3DMark05 score of 9,202 is genuinely impressive. Importantly, the 512MB card is capable of smoothly running just about any game at resolutions of 1,600x1,200 and with high levels of anti-aliasing and anisotropic filtering. Crucially, that’s not something you can say about the 256MB version of the 7800 GTX.

Should you be willing to spend the best part of a thousand pounds on improving your PC’s 3D rendering performance, you have the option of buying a pair of these cards and running them in SLI configuration for even more pixel-pushing power.