Radeon R5xx 3D programming guide released

Wikipedia has a good comparision of GPUs.
http://en.wikipedia.org/wiki/Comparison_of_ATI_Graphics_P...

It's nice to be able to tell the differences in memory bandwidth and clock speeds and other
features. It often helps when picking out cards.

A old example is the fact that for the R200 series cards the fastest one you could get was the
8500. The later ones, like the 9200, were actually designed more for cost effectiveness then
performance.