The Intel Core Ultra 5 245K is the objective winner of this comparison, securing victory in ten out of sixteen measured specifications. Its most significant technical advantage is its L2 cache, which is 247% larger than that of the Intel Core i5-12400. This substantial increase in cache capacity represents the primary performance differentiator between the two processors, establishing the newer model as the superior option based on the provided hardware specifications.

Users prioritizing raw cache capacity and the latest architectural specifications should select the Intel Core Ultra 5 245K for their build. Conversely, the Intel Core i5-12400 remains the better choice for those who prioritize power efficiency, as it maintains a 48% advantage in TDP. Choosing between these two components depends entirely on whether your specific requirements favor the increased cache performance of the newer model or the lower power consumption profile of the older unit.