The difference between a two-level cache and a level three cache

First of all, learn how to teach computer caching working principle?

Computer caching is when the CPU reads the data, first from the cache file, and then automatically read in the input to the CPU processing, of course, if not in the cache to find the corresponding cache file, it will be read from memory and transmitted to the CPU to deal with. Of course it takes a certain amount of time so it will be very slow. After CPU processing, it is very expensive to save this summer's data block in a cached file, so that the data will be read directly in the cache, so do not repeat in memory calls and read the data.

Understand the role of computer caching, for computer caching is divided into one level, two level, three level cache. So small series on the cache to introduce it.

The first level cache is built inside the CPU and runs at the same speed as the CPU, which can effectively improve the running efficiency of the CPU. The greater the level of cache, the higher the efficiency of the CPU, but limited by the internal structure of the CPU, the capacity of the first cache is very small.

The so-called level two cache, which is to reconcile the level of cache and memory speed. CPU call caching is first-level cache, not enough when the processor's speed gradually increased, resulting in a level of cache can not supply the demand, so as to upgrade to level two cache. Second-level caching it is slower than first-level caching, but it is larger than the amount of space in a first-level cache. The main is to do a level of cache and memory of the temporary exchange of data between the place.

The same is true for level three caching. is a cache that is designed to read data that is not hit by a level two cache, and only about 5% of the data in a CPU with level three cache needs to be called from memory, which greatly improves CPU efficiency.

Now we analyze the current mainstream CPU processor caching, if you use the AMD Model CPU processor generally only one or two levels of cache, there is no level three cache. If it is an Intel processor, it is usually only a level two or three cache. But Intel's high-end processors are only tier one and level three cache. So these are for everyone to understand.