Everything you wanted to know about the Radeon 9500 - X1900 but were afraid to ask. (PDF)
The reason I love this document so much is the scope it covers: exactly how the hardware is different from the specs. One of the tricky aspects of programming advanced OpenGL applications these days is that a lot of the fine print can't be expressed in terms of the extensions. For example:
- The R300/R400 (X100-X850) GPUs will render to floating point bufferers, but do not provide alpha testing, alpha blending, or fog on the back end of the frame buffer.
- The R500 GPUs (X1000-X1900) will render floating point buffers with alpha and blending but only if the floating point buffer is 16 bitgs, not 32 bits. Fog is still not an option.
One thing I learned that I would never have figured out: glClear gives better fill rate than simply over-painting the Z buffer on the R300.
The document even discusses internal precisions. (Hey X-Plane users...this is why your water looks "square" and "pixelated" on pre-X1000 Radeons; lower internal floating point precision and other R300/R400 hardware limititations.)
As far as I know, this is the closest thing by nVidia.