The Intel Core i3-14100 is the objective winner of this comparison, securing victory in eleven out of fourteen measured specifications. Its most significant technical advantage is the L2 cache, which is 233% larger than that found in the Intel Core i5-9400F. This substantial improvement in cache capacity provides the primary performance edge for the newer processor across the majority of the evaluated metrics.

Users prioritizing modern architecture and the superior L2 cache capacity should select the Intel Core i3-14100 for their build. Conversely, the Intel Core i5-9400F remains the appropriate choice for those who specifically require a higher total core count, as it offers a 50% advantage in that category. Your final decision should depend on whether your specific workload benefits more from the increased cache efficiency or the additional physical cores.