The Intel Core i5-14600KF is the objective winner of this comparison, securing victories in ten out of fourteen measured specifications. Its most significant advantage over the Intel Core i5-8400 is its L2 cache capacity, which is 1233% larger. This substantial increase in cache memory provides the primary technical edge for the newer processor, distinguishing it as the superior component across the majority of the evaluated performance metrics.

Users prioritizing high-performance computing should select the Intel Core i5-14600KF to leverage its massive L2 cache advantage. Conversely, the Intel Core i5-8400 remains a viable option for those specifically seeking a lower Max Turbo Power, as it holds a 64% advantage in that category. Choosing between these two components depends on whether your workload requires the expanded cache capacity of the newer model or the power efficiency profile of the older unit.