> (well, actually MSAA allows the GL to avoid having to do this to everything, and only do it for some buffers)
MSAA is faster than supersampling because the GPU generates subsample coverage but doesn't individually shade each subsample. And, this is absolutely critical, there is a compression scheme for depth and color transmission between the DRAM and texture cache which is a massive bandwidth optimization in the common case where a sample tile (usually 8x8, which for 4x MSAA corresponds to only 4x4 pixels) is covered by only one or two triangles.
MSAA is faster than supersampling because the GPU generates subsample coverage but doesn't individually shade each subsample. And, this is absolutely critical, there is a compression scheme for depth and color transmission between the DRAM and texture cache which is a massive bandwidth optimization in the common case where a sample tile (usually 8x8, which for 4x MSAA corresponds to only 4x4 pixels) is covered by only one or two triangles.