The Intel Core i3-14100F is the objective winner of this comparison, securing victories in eleven out of fourteen measured specifications. Its most significant technical advantage is its L2 cache, which is 233% larger than that of the Intel Core i5-8400. This substantial cache improvement serves as the primary driver for the superior performance profile of the newer processor across the vast majority of the evaluated metrics.

Users prioritizing modern architecture and cache-heavy tasks should select the Intel Core i3-14100F for its clear lead in overall specifications. Conversely, the Intel Core i5-8400 remains a viable alternative for specific workloads that rely heavily on a higher total core count, where it maintains a 50% advantage. Choosing between these two components depends entirely on whether your specific computing needs favor the increased cache capacity of the newer model or the higher core count of the older unit.