The Intel Core i7-14700 is the objective winner of this comparison, securing victories in nine of the fourteen evaluated categories. Its most significant technical advantage is the L2 Cache, which is 1767% larger than that of the Intel Core i5-8400. While the Intel Core i5-8400 holds a 70% advantage in Max Turbo Power, the superior cache capacity of the Intel Core i7-14700 establishes it as the more capable component across the majority of the measured specifications.

Users prioritizing high-capacity cache for complex processing tasks should select the Intel Core i7-14700 to leverage its substantial architectural lead. Conversely, the Intel Core i5-8400 remains the appropriate choice for those specifically seeking the power efficiency profile defined by its Max Turbo Power advantage. By evaluating these two distinct strengths, buyers can align their selection with either the raw cache capacity of the newer model or the specific power characteristics of the older unit.