Level 3 cache definition
Level 3 cache is a type of cache memory used in computer processors to store frequently accessed data and instructions. It’s positioned between the CPU and RAM, and serves as the third tier in the multi-level cache hierarchy, following level 1 (L1) and level 2 (L2) caches.
How level 3 cache works
L3 cache stores a larger set of data than L1 and L2 caches, but at slightly slower speeds. When the CPU has a request for some data, it first checks the L1 cache, then the L2, and finally the L3. If the data is found in the L3 cache it is fetched directly from there, so there’s no need to access the main memory, which would significantly slow down the entire process.
History of multi-level caches
As computing demands grew and processors became more powerful, it increased the gap between CPU speeds and main memory access times. Multi-level cache systems were introduced to even it out. L3 cache emerged as an additional layer to L1 and L2, and was meant to improve performance even further. It became especially useful in multi-core processors where it often acts as a shared cache for all cores.