The Intel Core i7-8700K is the objective winner of this comparison, securing more individual specification victories than the Intel Core i5-9400F. While both processors share several identical technical characteristics, the most significant performance advantage belongs to the i7-8700K, which offers 100% more threads than its counterpart. Conversely, the i5-9400F holds a notable edge in affordability, boasting an MSRP that is 56% better than the i7-8700K, making it the more cost-effective option for budget-conscious builders.

Users prioritizing heavy multitasking or demanding workloads should select the Intel Core i7-8700K to leverage its superior thread count. This component is better suited for those who require the highest level of technical capability provided in this comparison. Alternatively, the Intel Core i5-9400F is the ideal choice for buyers who want to maximize their savings, as its lower MSRP provides a significant financial advantage while still maintaining parity with the i7-8700K across half of the measured specifications.