The GeForce3 chip is quite an incredible thing. The core runs at a lively 200MHz, which is actually slower than the GeForce2 Ultra, which runs at 250MHz, but it has gone through some significant architectural changes that improve performance and open up whole new worlds in image quality features. The main new feature is its nfiniteFX Engine, which is optimised specifically for DirectX 8, with new Vertex and Pixel Shaders, both of which are programmable. The Vertex Shader allows fine manipulation of the 3D polygons in a scene,while the Pixel Shader manipulates the textures and effects that are applied to the 3D objects. Being programmable means that the 3D artist and programmer can specify exactly which effects they want to use, and can customise their own effects.

The second major new feature of the GeForce3 is its Lightspeed Memory Archi-tecture, which optimises the way memory is used by breaking up memory access into four 32-bit channels. This dramatically improves performance when the chip is dealing with many small memory accesses. The z-buffer has also been revamped to improve memory usage, and to save from rendering pixels that will never end up being displayed anyway.

Finally, the GeForce3 features a new method of performing FSAA (Full Scene Anti Aliasing), or the removing of jaggies from low resolution objects, called quincunx. This takes a sample of the four pixels located at the corners of the pixel to be rendered, and blends them together. This gives results similar to 4X FSAA at the performance of 2X FSAA.

In performance terms, we ran up the Hercules 3D Prophet III on our Pentium III/1GHz testbench and compared it to the previous fastest card we have seen, the GeForce2 Ultra-based Hercules 3D Prophet II Ultra. In 3DMark2000 Pro and Quake III, the GeForce2 Ultra managed to beat the GeForce3 at 800 x 600 at 16-bit colour by four per cent in both tests, due to the GeForce2 Ultras faster core clock. At 1,600 x 1,200 at 32-bit colour, however, the GeForce3 simply flew into the lead, coming in 24 per cent faster in 3DMark, and 55 per cent faster in Quake III, which is a direct result of the optimised memory usage. We also ran the new 3DMark2001 Pro benchmark, which has been specifically optimised for DirectX 8, and the performance is stunning, with the GeForce3 maintaining a consistent 45 per cent lead at all resolutions.

Unfortunately, there is no such thing as a free lunch, and the GeForce3 comes at a hefty price premium of $1,199. If you really must have the fastest damned graphics card in the world, then the GeForce3 is for you. Keep in mind, however, that many of the new GeForce3 features need to be supported in software, and this might take some time to happen. You can also expect other board manufacturers to release cards in the next few months, although these will be mainly differentiated by their driver tweaks and software bundles.

Tim Dean