The be quiet! Pure Base 500DX is the objective winner of this comparison, securing a lead in six out of eight evaluated specifications. Its most significant advantage over the competition is its storage capacity, offering 150% more 2.5" drive bays. This superior hardware configuration makes it the more versatile option for users who prioritize internal expansion and drive density within their system build.

Users requiring extensive storage support should choose the be quiet! Pure Base 500DX to take full advantage of its superior bay count. Conversely, the Corsair 4000D Airflow remains a viable alternative for those who do not require the specific storage benefits provided by the winning model. Selecting between these two cases depends entirely on whether your build configuration necessitates the additional drive capacity offered by the leading component.