Now let’s estimate how big the performance hit will be with enabled FSAA:
NVIDIA GeForce FX 5900 Ultra boasts twice as small performance hit in case of the most widely spread anti-aliasing 4x mode. The reasons are more than evident: unlike NV30, NV35 features a faster 256bit memory bus and enhanced caching schemes, Z-buffer and frame buffer compression.
In fact, we could expect NVIDIA GeForce FX 5900 Ultra to show even higher advantages in 8x mode, however, the supersampling algorithm used in 8x mode doesn’t let these expectations come true. Unlike multi-sampling, supersampling loads the graphics core in the first place, and here NV35 doesn’t boast any advantages over the predecessor. As a result, NVIDIA GeForce FX 5900 Ultra is only a tiny bit faster than NVIDIA GeForce FX 5800 Ultra, while the performance losses in this case are far from being optimistic.
ATI RADEON 9800 Pro uses “pure” multisampling, that is why even in the toughest 6x mode no unpleasant surprises occur.
To estimate the performance hit during forced full-screen anti-aliasing in Direct3D we will again turn to Unreal Tournament 2003:
Very interesting: 4x full-screen anti-aliasing by NVIDIA GeForce FX 5900 Ultra provides almost the same performance hit as 2x FSAA by NVIDIA GeForce FX 5800 Ultra.
ATI RADEON 9800 Pro works almost as efficiently with enabled FSAA as NVIDIA GeForce FX 5900 Ultra.
So, with the launching of the new NVIDIA GeForce FX 5900 Ultra full-screen anti-aliasing with the help of multi-sampling turned almost completely “free”, as the maximum noticed performance hit with 4x FSAA notched only 30.7%.
However, we can’t say the same thing about the most desired 8x FSAA mode: 8x FSAA in OpenGL and Direct3D eats up from 60% to 80%.of performance. This way, NVIDIA GeForce FX 5900 Ultra hasn’t become any better than the predecessor in 8x full-screen anti-aliasing modes.