The AMD Ryzen 9 9900X and the Intel Core Ultra 9 285K result in an objective tie across the provided specifications. While both processors demonstrate competitive parity, the most significant performance differentiator is found in their cache configurations. The AMD Ryzen 9 9900X holds a substantial lead in L3 cache capacity, which is 78% better than its counterpart. Conversely, the Intel Core Ultra 9 285K offers a massive advantage in L2 cache, exceeding the other by 233%.

Users prioritizing L3 cache capacity should select the AMD Ryzen 9 9900X for their build. This component is best suited for tasks that benefit from its specific cache architecture. Alternatively, those who require the superior L2 cache density provided by the Intel Core Ultra 9 285K should choose that model instead. Since both processors offer an equal number of winning specifications, the final decision depends entirely on which cache advantage aligns with your specific computing needs.