Short for FIFO buffer, the F-buffer is what gives the 9800 Pro the capability to do multi-passes
inside the pixel-shader engine instead of over the entire pipeline. With the 9700, the card had
to do the entire rendering proceedure with each pass. The 9800 Pro's F-buffer streamlines this
so that you do each step only once per pixel, making the card a lot more efficient.
While this is all fine and dandy, it is unlikely that games in the immediate future will take
advantage of the F-buffer but as DirectX 9.0 and OpenGL 2.0 become more of a requirement,
more support for the F-buffer and long shaders will emerge.