How do we make memory fast?

• The CPU is the main source of requests for information from the memory.
• The CPU is much, much faster than most memory systems.
• Although both the CPU and memory have gotten faster over the years, the speed of the CPU has grown much more quickly than the speed of memory.

Computer designers have been forced to invent clever ways to help the memory keep up with the CPU. One important technology that has helped solve this problem is the storage hierarchy.