The late introduction of R520 had caused ATI to speed up the introduction of its new products. Going by how the company handles kicker products, most of us assumed it would be just that; a refresh of the older SKUs. All in all, it was a hasty and wrongful assumption. ATI had been actually cooking something tasty for us ? R580 which has been in production since November 30th 2005
The increase in Arithmetic Logic Units to Texture Units (3:1 from 1:1) is a step in a right direction where more recent shaders tend to carry heavier proportion of arithmetic instructions (example, F.E.A.R). Next generation game titles will most likely go even further and use additional math operations on the data. With 48 pixel shader processors new fetch4 texture lookup and parallax occlusion mapping ATI seems to be set for the near future -- unless NVIDIA decides to walk ATI's path (it's very likely it will) or even surpass its ALU:Tex ratio. There is the other side of the coin however. Many will consider 16 Texture Units to be a limiting factor for R580. That's logically correct, but with newer applications it's the GPU with less ALUs that's going to be a bottleneck. X1900 XT from PowerColor