A "balanced" computer system used to follow the "one second" heuristic. (Is this named after somebody?) That is you should be able to offload temporary memory (core) to permanent storage in one second. And it should be able to execute a computation on every element of memory in one second too. I know this has held up through the gigaword generation. Leading edge computers, like a supercomputer, may be unbalanced where one of these factors lags.