1 hour ago, Pilpel said:
If it stores N times more colours, how is it different that SSAA?
For what I know, in SSAA that color is calculated per each pixel with the image being 4 times higher resolution if we talk about 4x SSAA and then downsampled to your actual resolution.
With MSAA you render the image at your monitor resolution (so you start with 4 time less calculation compared to above) and then for each pixel of that, the same calculated color is shared for each of the 4 sub-pixels based on visibility (using depth buffer, 4 times bigger) and coverage (is the subpixel inside or outside the polygon?), and then the 4 sub-pixels(my example is 4xMSAA) are averanged togeter to get the final color, and all this check and averange is apparently less expensive than actually calculating the real lighting for 4 pixels, since you do 1/4 of the heavy calculation only once compared to SSAA.
Take it as a grain of salt, I am begginner in this.