Originally posted by Chalnoth
What I'm trying to say is that a technique that is invariant in rotations about the z-axis doesn't need to be noticeably slower than a technique like that seen in the Radeon 8500 or Radeon 9700.
I think I should point out that, as you stated previously about some similar statement, you probably don't have all the necessary information to make such a definitive statement. That might be
the case, but just because you "can't see any reason" doesn't mean that a reason doesn't exist.
NV has had this capability since the GeForce. Do you really
think that time constraints were the primary issue? For how many years? Sure, it looks obvious to you that after so many years they should have been able to "figure it out" or "do it right," but in all likelihood there was a reason years ago not
to do it that way, and that fundamental reason hasn't changed, hence their implementation hasn't fundamentally changed.
In other words, IMO, it's much more likely that there is some substantial trade-off between the two methods such that they made an informed decision to go the route they did. I doubt this trade-off was due to the time required to do it (hundreds of hardware designers over several years, and they just couldn't squeeze it in?), or due to their lack of understanding of 'how' to do it. That leaves (1) transistor count, (2) performance, (3) some other unknown variable.
I can't imagine what that other variable might have been, but that doesn't negate the possibility that I (and you in your infinite wisdom as well) simply are not aware of it. Or is could be (1) or (2)...