The Intel Core i3-12100F 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 alternative. While the Intel Core i5-9400F maintains a lead in total core count by 50%, the superior cache capacity and overall spec dominance make the newer processor the more capable choice across the majority of measured categories.

Users prioritizing modern architecture and the substantial cache advantage should select the Intel Core i3-12100F for their build. Conversely, the Intel Core i5-9400F remains the appropriate choice for those whose specific computing requirements rely primarily on a higher total core count. By evaluating these two distinct hardware strengths, builders can align their selection with the specific technical demands of their intended workload.