The two major graphics competitors are gradually setting the stage for their next showdown, as nVidia prepares its G80 chip and ATI arms its R600 boards. This next batch of chips will be important for both companies as it will usher in the DirectX 10 era and will offer Shader Model 4.0 support.
nVidia has now confirmed that its G80 chip is taped out and the first chips are being produced, suggesting that the U.S. giant will be first to market with its DX10 product this coming September. ATIs R600 chip will attempt to serve as the acting Nemesis for the G80 but is expected later, possibly in November 2006.
What makes this battle even more intriguing is that this time nVidia and ATI will have some major design differences in their chips and those differences could help tip the graphics war balance one way or the other. The main difference lies in the way the chips will process pixel Shaders, geometry instancing and vertex information. ATIs design is expected to adopt the unified Shader model which allows for flexibility by utilising 64 unified Shaders. This way the chip has 64 pixel lines available per clock. It can use those in any ratio it needs to meaning that, for example, 30 can be pixel, 20 vertex and 14 geometry lines per clock cycle. nVidia's design however, challenges the unified Shader model and will use a more rigid design of 32 pixel Shaders and 16 vertex and geometry lines per clock cycle.
These details are not expected to have an immediate impact on DX10 as it is higher level but they may lead to a speed advantage for either of the competitors, an advantage which will only be apparent in the most demanding applications and at the highest possible settings so don't wear your eyes out trying to figure it out.