The Intel Core i9-14900KS is the objective winner of this comparison, securing nine spec victories compared to three for the Intel Core i5-12400. The most significant technical advantage held by the i9-14900KS is its L2 cache, which is 327% larger than that of its counterpart. While the i5-12400 maintains a lead in MSRP, offering a 73% better value in that specific category, the i9-14900KS dominates the overall hardware specifications provided.

Users prioritizing raw technical capacity and the substantial L2 cache advantage should select the Intel Core i9-14900KS for their build. Conversely, the Intel Core i5-12400 is the appropriate choice for budget-conscious buyers who value the 73% MSRP advantage over the higher-end specifications found in the more powerful model. Choosing between these two processors depends entirely on whether your primary requirement is maximizing cache-heavy performance or minimizing the initial cost of the component.