[twomoretime]

You can use hybrid systems where, say, memory is conventional RAM but computation (maybe full cpu or submodule like apu) is done with photons. You can probably perform large numbers of concurrent operations by taking advantage of the wavelike properties of photons.

[ip26]

You can wave pipeline electrons too. It just very rapidly becomes an impossible design problem as the complexity of your design increases (and as the variation grows in significance with node shrinks)