You need to use AMD' DSR, assuming you have an AMD GPU. SSAA is different. It's a form of AA. Though, I still recommend you enable DSR when playing games.
SSAA, the most primitive, supersampling renders the scene at a much higher resolution than the one displayed and down-samples the image using multiple samples to produce each pixel. There are quite a few downsampling patterns available, grid and rotated grid being two that are commonly used in games.
The first pattern splits each pixel into several sub-pixels and uses samples from each sub-pixel’s centre to produce the output. Rotated grid is a bit more sophisticated, as the sample pattern is rotated to keep samples from aligning. This can improve...