Cache levels

Caches that are used in computers are fast pools of memory that are designed to speed up the transfer of data between fast and slower devices. Aside from being used to buffer data, caches can possess software support logic, enabling them to begin processing procedures in advance.
Most of the modern computer  use two or three cache levels so that processor does not have to wait for longer time for information from the memory.

                 Different types of cache levels are:-

L1 Cache :-  L1 or Level 1 cache is referred to the cache which is built in the processor. This is the fastest cache in the computer. This cache is also known as primary cache or internal cache. The most common size of this type of cache memory is 8 KB to 64 KB.

L2 Cache :-  L2 or Level 2 cache was located outside the processor i.e. commonly present on the motherboard. The most common size of this type of cache memory is 64 KB to 8 KB. L2 cache can also reduce data access time by buffering the data that processor is about to request from memory, as well as program instructions. L2 cache is secondary to the CPU and is slower than L1 cache, despite often being much larger. In addition, data that is requested from L2 cache is copied to L1 cache. Requested data is removed from L2 cache if it is an exclusive cache, and stays there if it is an inclusive cache. L2 cache is most often unified, which means that it is used to store both program data and instructions.

L3 Cache :-   L3 or Level 3 cache all modern processor have L2 cache on them, thus the cache on the motherboard is referred to as L3 cache. Often only high end workstations and servers need L3 cache. Currently only the Pentium 4 Extreme Edition features L3 cache. L3 has been part of the CPU or externally mounted near the CPU on the motherboard. It comes in sizes and speeds.

            L3 cache is a memory cache that is built into the motherboard. It is used to feed the L2 cache, and is typically faster than the system's main memory, but still slower than the L2 cache.

  

  

Different Cache Levels