One of the features that many said was missing from 3dfx's Voodoo3 chip was the ability to render in 32-bit color. We can recall back then, in the days when Quake II and Half-Life boasted top-of-the-line graphics, that not many games utilized 32-bit rendering. Seeing this, 3dfx had neglected to include support for 32-bit rendering, which, basically, made the Voodoo3 much-less future-proof than it's competing product, the TNT2 from NVIDIA. This fact, I think, contributed considerably to the downfall of 3dfx and the rise of NVIDIA.

Since then, we haven't seen a single new product without 32-bit rendering support. NVIDIA had that support dated all the way back to their original TNT product, ATI introduced 32-bit rendering in their Rage128 and, later, improved on it on their Radeon and even 3dfx has come onto the scene, albeit too little too late, with their Voodoo4/5 products.

Unfortunately, all of the above-mentioned products still show a considerable performance loss when rendering at 32-bit, simply because they are using the conventional method of rendering. The reason why there is such a considerable loss in performance lies in the z-buffer, once again. To refresh our short-term memory, using conventional rendering, when the scene finally hits the stage where it utilizes the z-buffer, the polygons have already been textured with the specified color-depth. Because of this, a polygon that has 32-bit textures will require the z-buffer to use up twice the amount of memory bandwidth than a polygon that has 16-bit textures applied to it.

With tile-based rendering, we must be reminded that the z-buffer is on-chip, therefore, not utilizing the slower memory bandwidth. Because of the fact that the z-buffer is on-chip, everything can be done in 32-bit mode without the need for double the memory bandwidth requirements that traditional accelerators require. In fact, even 16-bit scenes are done in 32-bit and then dithered down to 16-bit when needed when using the KYRO. This is what Imagination Technologies and STMicro call Internal True Color and allows for superior 16-bit rendered image quality over conventional 3D accelerators.

On to: Mammoth Multi-Texturing