X-bit labs

ATI RADEON X800: R420 Totally Exposed (page 19)

Category: Video

by Tim Tscheblockov , Alexey Stepin , Anton Shilov

[ 05/04/2004 | 06:42 AM ]

The third fragment features a 45^o angle. The screenshots again follow like this: ATI RADEON X800 XT Platinum Edition, RADEON 9800 XT, NVIDIA GeForce 6800 Ultra and NVIDIA GeForce FX 5950 Ultra.

FSAA 2x

FSAA 4x

FSAA 6x/8x

In 2x mode the NVIDIA based graphics cards provide the worst anti-aliasing quality. Since in 2x mode they are locating the samples along the same diagonal as the polygon edge in this fragment, there appears hardly any anti-aliasing effect at all.

The ATI based graphics cards provide a somewhat better image quality: they locate the samples along a different diagonal.

When we shift to 4x mode, the graphics cards start showing much better anti-aliasing quality. The jaggies are least visible by those cards, which use rotated-grid sampling algorithm, i.e. by RADEON X800 XT/9800 XT and GeForce 6800 Ultra.

In 6x/8x modes ATI based graphics cards show subjectively better image quality as they use rotated-grid multi-sampling with 6 samples, while NVIDIA based graphics cards enable a combination of super-sampling and multi-sampling with the traditional subpixels location.