ATI Technologies X3-256 - 100-505096 FireGL 256MB AGP 4x/8x Dual DVI Graphics Card User Manual page 36

30 ATI Advanced Settings Tab
The Advanced Settings Tab
How to Use SMOOTHVISION™
The Application preference setting provides OpenGL® and Direct 3D®
applications with the ability to enable anti-aliasing automatically. If an
application does utilize an anti-aliasing setting, it is disabled. This option
results in high-quality images at the price of a negligible reduction in the
application's performance.
When Always on is enabled, you can apply anti-aliasing using different
sample patterns and sample points such as 2X or 4X. Moving the slider to
the right increases sampling to provide the most realistic 3D image, at the
cost of overall 3D performance.
Note: The Always on setting overrides an application's anti-aliasing
setting.