Originally Posted by Wildside
that's not true, u can see a differ when it goes higher. I've seen demo screenshots of 24x custom AA from AMD long before R600. The screens were comparing a chapel building in some game *dont remember* with no AA, 2x AA, 4x AA, 16x AA, n 24x AA - 24x AA screenshot looked amazing!!
I think the biggest quality differences, will be because of the different methods of anti-aliasing, rather than the actual level.
All anti-aliasing does, is try to remove jagged edges, by averaging pixel colour values from pixels around it, for pixels that lie on an edge of an object.
Beyond about 4X AA, what'll start to happen often is it will 'cut in' to objects in the foreground. Which is especially bad for thin or wire objects, which can sometimes be blurred too much.
conventional anti-aliasing also doesn't usually work too well when there are textures used for fences, and leaves and stuff, which are actually made of partially transparent textures.