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Different between Buffer and Cache

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Buffer
 It is an area of computer’s memory or devices memory for holding data during data transfer. Normally I/O devices have low speed than processor. This speed adjusted by having temporary data storage in a memory typically called buffer. While the device is in operation data transfer can take place in buffer. The process of holding data temporarily during I/O operation is called buffering. Because of buffering , I/O channels place data in buffer and the processor or I/O devices can access data from the buffer.

       Cache Memory
The cache memory is placed in between CPU and main memory. It is a semiconductor memory. It consists of static RAMs. It is a special and very high speed memory that is used to increase the speed of processing by making current program and the data available to the CPU at a rapid rate. Cash memory holds the frequently used instruction and data so that it can provide CPU at a faster rate. It is fabricated along with the CPU so works same as the speed of the CPU.CPU speed is usually faster than main memory speed, with the result that the processing speed is limited primarily by the speed of the main memory. So, the use of cache memory let the processor work in its actual speed.
To access main memory the CPU sends an address to it. In response of this the main memory sends data contained at the specified memory address. On the other hand cache memory uses parallel searching of the required data. It first compares the incoming address to the addresses present in the cache. If the address matches , it is called cache “hit”. If the data does not match, is called cache “miss”. When miss occurs, the data is read from the main memory. The data read from the main memory also written to the cache memory, so that when this specific address is accessed next time hit occurs. The hit ratio is defined as the ratio of the number of hits to the total number of read requests sents to the cache memory by the CPU.


Difference between Buffer and Cache:

                  Buffer
                 Cache
1.processing speed in slower than cache.
1.processing speed is high.
2.area of RAM or devices memory.
2.placed between processor and main memory.
3.currently in operation data holds.
3.frequently used instruction loaded.
4.adjust speed difference between processor and Devices.
4.let the processor work in its actual speed.
5.make temporary data storage in a memory.
5.eg.L1,L2,L3 caches,
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