Serious Sam: Second Encounter

Here we'll look at SS:SE under OpenGL.




FPS 640x480 800x600 1024x768 1280x1024 1600x1200
1.0.0.233 72.6 71.4 66.0 51.9 36.8
1.2.0.42 60.9 60.0 59.4 47.9 34.8
 
Difference 640x480 800x600 1024x768 1280x1024 1600x1200
FPS -11.7 -11.4 -6.6 -4.0 -2.0
% -16% -16% -10% -8% -5%

Again, we can see that the later drivers are performing, on average, worse than the earlier set. Here, with the newer drivers, the performance at 1024x768 is just below 60 FPS whilst it's still above 30 FPS at 1600x1200.





1.2.0.42 640x480 800x600 1024x768 1280x1024 1600x1200
Normal 60.9 60.0 59.4 47.9 34.8
2X Aniso 60.1 59.0 53.9 39.7 28.3
16X FAA 59.7 59.5 54.9 42.2 30.5
2X Aniso + 16X FAA 61.6 59.0 50.7 35.5 24.5
 
% Difference 640x480 800x600 1024x768 1280x960 1600x1200
2X Aniso -1% -2% -9% -17% -19%
16X FAA -2% -1% -8% -12% -12%
2X Aniso + 16X FAA 1% -2% -15% -26% -30%

SS:SE uses up to five texture layers, so with Trilinear filtering it's probably already using more samples than the four texture units per pipe can handle in one pass, so doubling the sampling requirements in this situation is bound to decrease the performance. Here we can see that at 1600x1200, the most fill-rate limited situation, a 19% performance drop occurs.

The penalty for enabling FAA in this case is actually less than for 2X Anisotropic filtering, with the higher performance penalty being only 12%. Adding both FAA and 2X filtering at the same time looks to give, more or less, a cumulative performance drop in this instance.