【 Weak current College 】 L1 cache and L2 cache differences

In order to distinguish between these two concepts, let's first look at the RAM. RAM and ROM, RAM is the blackout, the information which the vanishing, the ROM in power-down after the information is not lost.

RAM is divided into two types of static RAM, SRAM, and the other is the dynamic RAM, DRAM. The former storage faster than the latter, we now use memory generally dynamic RAM.

Some rookie said, in order to increase the speed of the system, the cache is not expanded, extended, the larger the cache of data, the more system not faster? cache are usually static RAM, speed is very fast, but static RAM integrated low (store the same data, static RAM size is 6 times the dynamic RAM), the price is high (with capacity of static RAM is four times the dynamic RAM), thus expanding the static RAM as the cache is a very stupid behavior, but in order to improve system performance and speed, we need to expand the cache so that you have a middle way, does not extend the original static RAM cache, but the increase in the number of high speed dynamic RAM for caching, these high speed dynamic RAM speed than conventional dynamic RAM, but more than the original static RAM caching slow, we put the original static ram cache called the L1 cache, and the subsequent increase of dynamic RAM called L2 cache.

L1 cache and L2 cache is an in-memory data access frequency high copy (map), their existence is to reduce high speed CPU on slow memory access. Usually find data or CPU instruction sequence is: first-level cache, find, find again to be found in the level 2 cache, if you still can't find it, only to find out in memory.