Saturday, February 7, 2009

Cache Memory

As all we know that,processing core and the memory are two integral parts of any CPU(Central Processing Unit).Now further this,memory is again divided into two categories slow memory and fast memory.Slow memory are RAM and hard disk,while Cache memory is the fast memory.The term slow and fast directly implies with the speed with which data can be accessed from these memory units.In simple words we can say cache memory is the memory that is used to store frequently used data so that the CPU doesn't have to wait for the data to be fetched from another slower storage areas like the system RAM or hard disk.

The main reason behind the fast accessing of data from cache memory is that it does not require refreshing of data and it is made of quite expensive static RAM.Once the data is stored in the cache, future use can be made by accessing the cached copy rather than re-fetching or re-computing the original data and this is what makes the average access time shorter. Cache, therefore, helps expedite data access that the CPU would otherwise need to fetch from main memory. The main advantage of cache memory is that performance of the CPU is increased to a great extent and it saves use of the read/write head which in turn extends its life too.Now a days cache memory is available in the range from 2 MB to 16 MB.