Originally posted by Behemoth
obviously, instead of putting this "shuffle instructions" optimization into PS2 shaders, ati chose to remove it in the next driver, which makes me believe the "shuffle instructions" optimization only works in GT4 scenario, it does not work for all combinations of parameters hence, they are not fully PS2 compliant shaders, hence i believe they also are cheats
I'm not understanding how you reached that conclusion. Perhaps you could explain it in more detail? What exactly constitutes a "fully PS2 compliant shader?"
My understanding is that as long as you run all the calls a DX9 shader asks for, it is still compliant. nvidia obviously lowered precision, and rewrote the shader code. ATI is not doing less work, as you seem to imply in another thread. They are doing the exact same amount of work they are supposed to do, with the exact same output.
Now, the question is whether this is cheating. In a benchmark, it could be. Just because your claim may be correct(that ATI is cheating), doesn't mean that you reasoning is(they are somehow not running PS2 compliant shaders).