This tag/index/offset address breakdown is exactly how real hardware cache controllers in every Intel, AMD, and ARM chip decide where data lives, and the conflict-miss pattern you trigger here is a real performance bug: array strides that happen to share a cache index, a classic problem in scientific computing and matrix code, can tank throughput to near-RAM speed. Understanding this simplest cache design is the prerequisite for the set-associative caches every real CPU actually ships.