The Anatomy of Modern Processors Cache Introduction Cache is a key to the performance of a modern processor. Cache should only affect the performance of a program.
All programs show some locality of reference .
This appears to be a universal property of programs - whether commercial, scientific, games, etc . Cache exploits this property to improve the access time to data and reducing the cost of accessing main memory. Once a location is referenced, there is a high probability that it will be referenced again in the near future. When an instruction or datum is accessed it is very likely that nearby instructions or data will be accessed soon. It's obvious that an instruction stream will exhibit considerable spatial locality.