Liangxu Linux

Jul 5, 2023 · Fundamentals

Why CPUs Need Cache Memory and How the MESI Protocol Keeps It Consistent

Modern CPUs use multi‑level cache memory to bridge the speed gap with main memory, relying on temporal and spatial locality, and employ the MESI protocol with states M, E, S, I to maintain coherence across cores, while techniques like store buffers and memory barriers mitigate latency and ordering issues.