CPU cache, main ram & disk are all treated the same at the software layer. All memory accesses are somehow expected (in theory) to be O(1).

The best you can do with such a model is try to predict space (access pattern etc). On the other hand, cellular automata would make it much more obvious and benefit both small & big programs.

Parallelism is ultimately the duplication of space. If one bucket isn't enough, you get a second one. But with our space-unaware ISAs you need some cooperation from your OS, all the layers above and predict as best you can.