The Western Digital WD Black SN850X 4TB is the objective winner of this comparison, securing more individual specification victories than its counterpart. While both drives share identical performance characteristics across most metrics, the 4TB model provides the most significant advantage by offering 100% more storage capacity than the Western Digital WD Black SN850X 2TB. This doubling of available space makes the larger drive the superior choice for users prioritizing maximum data density for their storage needs.

Users who require extensive room for large libraries or professional media files should select the Western Digital WD Black SN850X 4TB to leverage its superior capacity. Conversely, the Western Digital WD Black SN850X 2TB is the better option for budget-conscious buyers, as it holds a 63% advantage in MSRP. Choosing between these two components depends entirely on whether your priority is minimizing initial expenditure or maximizing the total amount of data you can store.