I believe it can'tJawed said:So on G70 can you dual-issue two MADs each of which has independent FP32 source operands (6 in total)?
You don't need a nvidia card to do this, I'm sitting in a internet cafe' nowCan you, as a matter of interest, take the HLSL from:
http://www.beyond3d.com/forum/showpost.php?p=294006&postcount=99
And report the shader performance stats for SM3 on G70?
Here the results about NV40:
Code:
-------------------- NV40 --------------------
Target: GeForce 6800 Ultra (NV40) :: Unified Compiler: v77.72
Cycles: 38.75 :: R Regs Used: 5 :: R Regs Max Index (0 based): 4
Pixel throughput (assuming 1 cycle texture lookup) 168.42 MP/s
=========================================================================
Shader performance using all FP16
Cycles: 37.75 :: R Regs Used: 4 :: R Regs Max Index (0 based): 3
Pixel throughput (assuming 1 cycle texture lookup) 172.97 MP/s
=========================================================================
Shader performance using all FP32
Cycles: 55.50 :: R Regs Used: 6 :: R Regs Max Index (0 based): 5
Pixel throughput (assuming 1 cycle texture lookup) 116.36 MP/s
G70:
Code:
-------------------- G70 --------------------
Target: GeForce 7800 GTX (G70) :: Unified Compiler: v77.72
Cycles: 36.00 :: R Regs Used: 4 :: R Regs Max Index (0 based):
Pixel throughput (assuming 1 cycle texture lookup) 286.67 MP/s
===============================================================
Shader performance using all FP16
Cycles: 33.00 :: R Regs Used: 4 :: R Regs Max Index (0 based):
Pixel throughput (assuming 1 cycle texture lookup) 312.73 MP/s
===============================================================
Shader performance using all FP32
Cycles: 50.50 :: R Regs Used: 6 :: R Regs Max Index (0 based):
Pixel throughput (assuming 1 cycle texture lookup) 206.40 MP/s
In the general case (I tested a LOT of shaders from nvidia demos and some game..) there's not that much difference going from partial to full precision since many shaders don't use more than 4 live registers.
You can do your own statistics: install nvshaderperf on your computer and have fun !
ciao,
Marco