What is cache memory?
Today I am going to introduce you the cache memory. In the computer, there is a processor and a memory. The processor is more speed compared to memory. But the problem is even though the processor is so high speed, the processor needs to work with the speed of memory. Because the processor needs to get data from memory. Therefore the processor becomes a bottleneck.
To address the above issue, people have invented very high-speed memory devices. But they are currently used in very small scale due to these memories high cost. Very high-speed memories compared to main memory are there and they are called registers and these are located very close to CPU. How this helps to CPU is it already fetch the instructions and store in the registers. But still, we have a problem that we cannot store everything in the registers since they are used in very small scale due to their cost.
To address this issue people invented another memory device called cache. this is not as speedy as registers but not slower like main memory. And also it is not high cost as registers and not cheaper like main memory. Therefore we use this memory to reduce the bottleneck. There can have many levels like this. Those come under cache level 1, level 2, level 3 and so on. Here the L1 means registers and level 2 is the cache memory and level 3 is random access memory.
Following diagram shows the overall system we talked so far.
