More Carmack on GeForce FX vs. Radeon 9700
The boys at Beyond3D have a few words from John Carmack clarifying some of his recent comments comparing the GeForce FX and Radeon 9700. The questions are excellent, and the answers are helpful, but this isn't for the faint of brain:
Why is the ARB2 path so slow on NV30? Just the higher precision alone doesn't seem to account for NV30's performance given that it runs at a much higher clock speed versus the R300 and 96-bit vs 128-bit is but a 33% difference.
Apparently, the R300 architecture is a better target for a straightforward assembler / compiler, while the NV30 is twitchy enough to require more serious analysis and scheduling, which is why they expect significant improvements with later drivers.
We'll see about that, eh? (Also, remember: they are sometimes talking about bit-depths in terms of bits per color channel, not total bit depth.)