you have some choices. you can either make the UV space 0-4 on the 4x4 or make the the UV space 0-.25 on the 1x1 then tile your texture 4x with UV coordinates in the material editor.
Its called texture resolution. Its about having the same pixel size on each object. So if an image is 512pixles on a 1x1 cube it will need to be tiled 4 times or a larger 2048 pixel image for a 4x4 cube.