[colanderman]

I think there is no distinction to be made. Consider encoding information in a 4-cube (hypercube) constrained by Maxwell's equations. (Let's make the space discrete so our heads don't explode.) You will find that you can only encode an amount of information proportional to the cube of the 4-cube's edge length, not the 4th power, because you are constrained by Maxwell's equations. If you further insist on keeping the information unchanged with respect to time, you'll be restricted to an amount proportional to the square of the 4-cube's edge length.