Can R420 perform more z-only/stencil ops/clk than NV40 w/AA?

[991060]

These don't seem correct to me. You're comments seem correct though. I think Nvidia and Ati are identical for 2x and 4x AA modes. Also, where did you get your color op numbers from? Shouldn't they all be 1 color op?

the data for R420 is obtained from here:
http://www.rage3d.com/board/showthread.php?s=&threadid=33762783

No AA
Z Fill : 5146.411 M-Pixel/s
Color + Z Fill : 3062.681 M-Pixel/s

2xAA
Z Fill : 4648.127 M-Pixel/s
Color + Z Fill : 2504 M-Pixel/s

4xAA
Z Fill : 2471.284 M-Pixel/s
Color + Z Fill : 2290.09 M-Pixel/s

6xAA
Z Fill : 1275.907 M-Pixel/s
Color + Z Fill : 1336.305 M-Pixel/s

So for R420:
No AA:
Z Fill = 5146/(475*12) = 0.9 = 1
C+Z = 3062/(475*12) = 0.53 = 1(remove bandwidth limitation)
2xAA:
Z Fill = 2*4648/(475*12) = 1.63 = 2
C+Z = 2*2504/(475*12) = 0.87 = 1(this number is quite weird)
4xAA:
Z Fill = 4*2471/(475*12) = 1.73 = 2
C+Z = 4*2290/(475*12) = 1.6 = 2
6xAA:
Z Fill = 6*1275/(475*12) = 1.34 =2
C+Z = 6*1336/(475*12) = 1.4 = 2

I did a lot approximation, maybe doing the test under lower core clock will give more idea numbers. I can't understand/explain the C+Z number in R420's 2xAA mode, it's just what's revealed by the data. As for the color ops alone, I assume sireric is right, but in most cases, you'll need to do z and color ops together, so 2 ops/clock is what you can hope for the best.

 

[akira888]

I did a lot approximation, maybe doing the test under lower core clock will give more idea numbers. I can't understand/explain the C+Z number in R420's 2xAA mode, it's just what's revealed by the data. As for the color ops alone, I assume sireric is right, but in most cases, you'll need to do z and color ops together, so 2 ops/clock is what you can hope for the best.

I think it's a fairly safe assumption that sir eric is right about R420.