The Memory Hierarchy
mem-o-ry: a device in which information can be inserted and stored and from which it may be extracted when wantedhi-er-ar-chy: a graded or ranked series
An idealized random access memory (RAM) has N words indexed by integers such that any word can be fetched or stored – using its integer address – equally quickly. Hardware designers can make a big slow memory, or a small fast memory, but a big fast memory is prohibitively expensive. Also, one thing that speeds up access to memory is its nearness to the ...