Caching is also very much not limited in usefulness to I/O-bound operations; a cache hit can save a great deal of CPU time, too, if you have difficult-to-comput

Caching is also very much not limited in usefulness to I/O-bound operations; a cache hit can save a great deal of CPU time, too, if you have difficult-to-compute values that are sufficiently static to be worth caching. Even if your whole dataset fits into RAM, you may still have that one O(2^N) algorithm that doesn't need to be run for every request. Voila! A perfect application for caching.