Since Microsoft announced their next generation console platform, XBOX 360, at this years E3 various aspects of the technology have been spoken of including “Xenos” (formerly rumoured as “R500”), the graphics processor for the console. ATI have been presenting some information on it so far and whilst one thing is clear, it is a very different graphics processor to those we have seen before, there is has still been very little understanding of what Xenos really is and how it works.

Beyond3D have spent some time with the lead architects of the graphics processor in order to gain a greater understanding of how Xenos works and in this article we hope to lay that out in a little greater detail. This article explores some of the operations of the graphics system, such as how the eDRAM module fits into the graphics processing and how it handles resolutions greater than the eDRAM size. We also take a look at how the unified shader architecture at the heart of Xenos operates and look at why ATI have implemented such a system and speculate on how this may affect upcoming PC graphics processors from ATI.