The Intel Core Ultra 9 285K wins in 11 out of 14 comparable specs. Its biggest advantage is L2 Cache (2567% better).
Core i5-8400 wins in 3 specs (Max Turbo Power: 74% better).
Recommendation
Choose Core Ultra 9 285K if you want the best overall performance — especially l2 cache.
Choose Core i5-8400 if max turbo power matters more to you.
