The L in L1, L2, and L3 stands for "Level", hinting at their hierarchical structure. The L1 cache is the fastest of the lot, with bandwidth close to 1TB/second and just 1 nanosecond of latency.

L1+L2 inclusive cache, L3 victim cache, write-back polices, even ECC. Source: Fritzchens Fritz Another aspect to the complexity of cache revolves around how data is kept across the various levels.

CPUs have a number of caching levels. We've discussed cache structures generally, in our L1 & L2 explainer, but we haven't spent as much time discussing how an L3 works or how it's different ...