What is Cache Memory In Computer ? Its Types, Level & Facts

What is CPU Cache

Memory of CPU, it's a smaller and faster memory that stores copies of data from RAM that is waiting to be used by the CPU. Basically, CPU cache contains a small area of memory with the instructions that the computer will most likely need next if it is to perform certain tasks. The main purpose of a cache memory is to ensure that CPU has immediate and instant access to the data it needs in the right order. So we can say that CPU cache is a temporary data store located directly on the processor.

How Does Cache Memory Work

Cache memory works as a middleman between CPU and RAM by efficiently storing common data and instructions. This storage allows for quick retrieval when needed. The underlying principle behind cache memory is locality of reference, which suggests that if data is accessed once, it is likely to be accessed again and again in the near future. When CPU needs to access data, it initially checks the cache memory. If the requested data is present in the cache, it is referred to as a cache hit. Consequently, CPU can swiftly access data from the cache, bypassing the slower main memory RAM. On the other hand, if the required data is not found in the cache, it results in a cache miss. In such cases, CPU must take the longer and slower route to access the main memory RAM to obtain data.

Types of Cache Memory

Typically divided into three levels.

Level 1 Cache

Level one cache, also known as primary cache. This is the smallest and fastest type of cache memory. It is embedded directly into the CPU, allowing it to operate at the same speed as the CPU.

Level 2 Cache

Level two cache, which is also called external cache. Level two cache is larger in size and slightly slower in speed compared to level one cache. In older computers, level two cache was located outside the CPU on a separate chip, but in modern computers it is located inside the CPU.

Level 3 Cache

Level three cache, also known as the last level cache. It is larger than both level one and level two caches but is slower. It is located on the CPU and is shared by all cores. Level three cache plays an important role in data sharing and intercore communications, whereas level one and level two caches are dedicated to their own CPU cores.

Important Facts

Cache is typically 100 times faster than the RAM. You cannot delete the CPU cache memory. The reason: it's a volatile memory. This means that it doesn't keep its contents in the long term. As soon as you switch off the computer, the content in your processor's cache memory is lost.