The AMD Ryzen 7 5800X3D is the objective winner of this comparison, securing victory in seven of the fourteen evaluated categories. Its most significant technical advantage is the L3 cache, which is 433% larger than that of the Intel Core i5-12400. While the Intel Core i5-12400 holds its own in several areas, the substantial capacity of the L3 cache remains the defining differentiator between these two processors.

Users prioritizing the massive L3 cache advantage should select the AMD Ryzen 7 5800X3D for their build. Conversely, those who find the 88% larger L2 cache of the Intel Core i5-12400 more relevant to their specific computing needs should opt for that component instead. Both processors offer distinct architectural strengths, and the final choice depends on whether the user values the superior L3 cache capacity or the specific L2 cache benefit provided by the alternative.