The AMD RX 6900 XT is the objective winner of this comparison, securing more category victories across the evaluated specifications. Its most significant advantage over the AMD RX 6400 is its shader unit count, which is 567% higher. While the smaller card holds its own in several metrics, the substantial lead in processing hardware positions the larger unit as the superior option for raw technical capability.

Choose the AMD RX 6900 XT if your primary requirement is maximizing shader unit capacity for your system. Conversely, the AMD RX 6400 is the logical selection for users who prioritize the 84% advantage in MSRP. By focusing on these specific strengths, you can align your purchase with either the high-end hardware density of the former or the cost-efficient positioning of the latter.