The Intel Core i5-14400 is the objective winner of this comparison, securing victories in ten out of fourteen measured specifications. Its most significant technical advantage is its L2 cache, which is 533% larger than that of the Intel Core i7-8700K. This substantial increase in cache capacity provides the primary performance edge for the newer processor, allowing it to outperform the older model across the vast majority of the evaluated hardware metrics.

Users prioritizing modern architecture and the efficiency of a significantly larger L2 cache should choose the Intel Core i5-14400. Conversely, the Intel Core i7-8700K remains a viable option for specific use cases that rely heavily on a higher base clock speed, where it maintains a 48% advantage. Selecting between these two components depends on whether your workload benefits more from the superior cache architecture of the newer model or the higher base frequency of the older unit.