What is Cache Memory ?

Compressed file :-)

cache memory is a very fast SRAM that sits between processor and main memory(usually DRAM).it helps increase the performance of the processor.

CACHE Memory is a very high spead and comparably expensive type of memory. It is used to speed up the performance of processors by allowing it them to use it as a "workspace" for comparably small amounts of information that must be worked uppon, stored, recalled, restored, etc, very frequently during some operations. If all this would have been done on external normal memory, your computer would be much - much slower.Now ask, why isn't all memory like CACHE memory?Well, because of the technology used, CACHE memory is bit-by-bit more expensive than - say - SDRAM or DDR memory. It would make PC prices skyrocket. What we usually have is maybe 500K up to 2 MB (even higher) of CACHE Memory and it usually comes inside the processor.Try it out -- check out prices of different pentium processors, where the only changes are in CACHE memory. Prices will vary significantly.

In computer science, a cache is a collection of data duplicating original values stored elsewhere or computed earlier, where the original data is expensive (usually in terms of access time) to fetch or compute relative to reading the cache. Once the data is stored in the cache, future use can be made by accessing the cached copy rather than refetching or recomputing the original data, so that the average access time is lower.Caches have proven extremely effective in many areas of computing because access patterns in typical computer applications have locality of reference. There are several sorts of locality, but we mainly mean that the same data are often used several times, with accesses that are close together in time, or that data near to each other are accessed close together in time.http://en.wikipedia.org/wiki/Cache_memory