Cache Over Algorithms: Why Hardware Architecture Shapes Real-World Performance

While developers traditionally optimize for algorithmic complexity, CPU cache architecture and memory access patterns often determine real-world performance more than big-O notation ever could. This deep dive reveals how cache line sizes, memory hierarchy latency, and data locality can deliver dramatic speed improvements—even when the algorithm remains unchanged. Understanding these hardware fundamentals is critical as performance bottlenecks increasingly stem from cache misses rather than algorithmic inefficiency.