Every Byte Matters

The author explains how understanding CPU cache architecture can dramatically improve performance beyond traditional algorithmic analysis. By examining cache line sizes (64 bytes) and memory latency, he demonstrates that iterating over an array of structs wastes cache space by loading unnecessary fields, whereas organizing data by field (struct of arrays) packs multiple relevant values into a single cache line, enabling 64 times more data access per fetch. This hardware-aware optimization shows that "every byte matters" when designing data structures for optimal performance.