The Intel Core i5-14500 wins in 9 out of 14 comparable specs, with 2 ties. Its biggest advantage is L2 Cache (1333% better).
Core i5-8400 wins in 3 specs (Max Turbo Power: 58% better).
Recommendation
Choose Core i5-14500 if you want the best overall performance — especially l2 cache.
Choose Core i5-8400 if max turbo power matters more to you.
