Terrain shader optimisation

It’s better and faster to use the default terrain texture splatting(1 for each channel) or to send to the terrain shader just 1 texture atlas and then unpack it here?

by default terrain takes 1 pixel 4 times from 4 different textures, then blends it based on splat mask.

using atlas you should not just take 4 pixels, but also pre-calculate mapping per texture to mapping for atlas and also take pixel 4 times.

so you just will get some more calculations, especially if source textures are different resolution