The graphics system uses the R500 GPU from ATI. Whilst all sorts of information has been flying round, here's what we know. R500 is an Xbox-only chip. R520, ATI's next PC part, is nothing like it. It won't be until R600 - possibly this time next year, or even early 2007 - that we see the Xbox-esque features on the PC. The GPU itself uses a unified shader architecture. That is, unlike PC graphics boards - which use a pixel shader pipeline and vertex shader pipeline - just one pipeline is used for both, which will, it is said, lead to more efficient programming and better performance.