The Intel Core Ultra 5 235F is the objective winner of this comparison, securing victories in eleven out of fourteen measured specifications. While the Intel Core i5-8400 maintains a 43% advantage in Max Turbo Power, the newer model dominates in memory and cache architecture. The most significant technical improvement offered by the Intel Core Ultra 5 235F is its L2 Cache, which provides a 1233% increase over the Intel Core i5-8400.

Users prioritizing modern architectural efficiency and significantly expanded cache capacity should select the Intel Core Ultra 5 235F for their system. Conversely, the Intel Core i5-8400 remains a viable option for specific builds where the higher Max Turbo Power capacity is the primary requirement. Choosing between these processors depends on whether your workload benefits more from the massive L2 Cache advantage of the newer chip or the power profile of the older unit.