The most dramatic effect of the T-Buffer engine is its ability to perform real-time full-scene spatial anti-aliasing in hardware. With non-anti-aliased 3D-graphics, when something is rendered, it is rendered to the nearest pixel. When something does not fall exactly onto one of those spaces, the position is approximated to the nearest pixel. When that something is a thin, black, diagonal line on a white background that often falls between two pixels, the computer approximates the location and you get a stair stepping effect known as the "jaggies." If you move that black line around slowly, you will see pixels popping in and out as the approximate location hops closer to one pixel than another. This is called "pixel popping."

What 3dfx's jittered anti-aliasing does is, instead of just approximating the pixel location once, it renders the image multiple times at slightly offset (jittered) positions into separate buffers, then combines the jittered images together to arrive at the final color for each pixel. So if you have the line falling half on a pixel normally, after the jittering FSAA process, that pixel will likely be a shade of gray. This reduces or gets rid of jaggies and pixel popping because the mind will see the anti-aliased line as smooth and diagonal, unless you look closely.

Another major advantage of anti-aliasing is the reduction of the shimmering effect. This effect is caused when a screen pixel is shared by multiple dots of a texture map. Normally, the computer will choose one dot to render that pixel, which can cause a shimmering effect when the texture moves slightly and contrasting dots from the texture map "take over" the pixel. With 3dfx's jittered anti-aliasing, just like with the pixels in a line, the jittering process combines multiple renders together to give smoother transitions and reduce the shimmering effect. This process can also eliminate moiré effects such as those you see in Star Wars Racer when passing the grandstand.

The Voodoo5 5500 PCI itself uses two and four-way Jittered Sub-Sample Anti-Aliasing (2WJSAA and 4WJSAA). According to 3dfx, 2WJSAA has the equivalent quality of four-way un-jittered SSAA, and 4WJSAA has the equivalent quality of 16-way un-jittered SSAA. In our experience, the main advantage of 3dfx's FSAA implementation is that it works in virtually all 3D applications, unlike the FSAA of other consumer cards. Also, 3dfx's FSAA causes less of a speed hit, though still a significant speed hit, and usually just looks better than that of the competition.