The Intel Core Ultra 9 285K is the objective winner of this comparison, securing victories in eleven out of fourteen measured specifications. Its most significant advantage over the Intel Core i5-8600K is its L2 cache capacity, which is 2567% larger. While the Intel Core i5-8600K maintains a 62% advantage in Max Turbo Power, the superior cache architecture of the Intel Core Ultra 9 285K makes it the more capable component across the vast majority of evaluated metrics.

Users prioritizing raw cache capacity and modern architectural advantages should select the Intel Core Ultra 9 285K for their build. Conversely, the Intel Core i5-8600K remains a viable option for those specifically seeking the power profile defined by its Max Turbo Power advantage. Choosing between these two processors depends on whether your requirements favor the extensive cache improvements of the newer model or the specific power characteristics offered by the older unit.