Cache size is also one of the important indicators of the CUP, and the structure and size of the cache has a very large impact on the speed of the CUP, the cache within the CUP is running at a very high frequency, generally the same frequency as the processor operation, the efficiency is much greater than the system memory and hard disk. In practice, the CUP often need to repeatedly read the same block of data, and the increase in cache capacity can significantly improve the hit rate of the CUP internal read data, without having to go to memory or hard disk to find, in order to improve system performance. However, due to the size and cost of the CUP chip, the cache is very small. & &

L1 Cache is the first level of cache on a CUP and is divided into a data cache and an instruction cache. The capacity and structure of the built-in L1 cache have a greater impact on the performance of the CUP, but the cache memory are composed of static RAM, the structure is more complex, in the case of the CUP core area can not be too large, the capacity of the L1 level cache can not be made too large. General server CUP L1 cache capacity is usually 32-256KB.

L2 Cache (L2 Cache) is the second level of the CUP cache, divided into internal and external chips. The internal chip L2 cache runs at the same speed as the main frequency, while the external L2 cache is only half of the main frequency.

L2 Cache capacity also affects the performance of the CUP, and the principle is that the bigger the better, the maximum capacity of the CUP for home use is now 512KB, while the L2 cache of the CUP for servers and workstations is even higher than 256-1MB, and some are as high as 2MB or 3MB.

L3 Cache is the second layer of the CUP, and it can be used as the second layer of the CUP, and it can also be used as the second layer of the CUP. >

L3 Cache (Level 3 Cache), there are two kinds, the early is external, now are built-in. The actual role of the L3 cache is to further reduce memory latency and improve processor performance for large data-volume calculations. Reducing memory latency and increasing the ability to compute large amounts of data are both very helpful for gaming. And in the server space adding L3 cache still provides a significant performance boost. For example, a configuration with a larger L3 cache utilizes physical memory more efficiently, so its slower disk I/O subsystem can handle more data requests. Processors with larger L3 caches provide more efficient file system caching behavior and shorter message and processor queue lengths

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