In performance-critical applications, the CPU cache can be your best friend—or your worst enemy. While algorithmic complexity often takes center stage, memory access patterns are equally crucial for ensuring high performance. Poor memory locality can lead to cache misses, stalling the CPU and slowing your application. This article dives into practical techniques for writing cache-friendly C++ code, enabling you to harness the full power of modern hardware. Why Cache Optimization Matters The CPU cache acts as a bridge between the processor and slower main memory, storing frequently accessed data to reduce latency. A high cache hit rate ensures your program runs efficiently, while cache misses force the CPU to fetch data from RAM, which can be up to 100x slower. By writing cache-friendly code, you can reduce latency, improve throughput, and optimize your application for real-world performance. How CPU Caches Work Underst...