One (somewhat obvious) disadvantage of supersampling is that it requires sampling four times as many points as usual. Some graphics renderers try to avoid this cost by detecting if the same triangle occupies the entire 2x2 pixel block or sharing computation between the four pixels. Some antialiasing techniques that attempt to be faster than supersampling (SSAA) at the cost of accuracy are MSAA, FXAA, SMAA, MLAA, SMAA T2x and TAA, which each make different approximations to avoid the cost of supersampling. The last two techniques are especially interesting because take into account temporal information from successive frames to enhance anti aliasing in motion.
One (somewhat obvious) disadvantage of supersampling is that it requires sampling four times as many points as usual. Some graphics renderers try to avoid this cost by detecting if the same triangle occupies the entire 2x2 pixel block or sharing computation between the four pixels. Some antialiasing techniques that attempt to be faster than supersampling (SSAA) at the cost of accuracy are MSAA, FXAA, SMAA, MLAA, SMAA T2x and TAA, which each make different approximations to avoid the cost of supersampling. The last two techniques are especially interesting because take into account temporal information from successive frames to enhance anti aliasing in motion.
More info about MSAA here:
https://en.wikipedia.org/wiki/Multisample_anti-aliasing