The portable SSD market has been steadily expanding thanks to the increasing digital footprint of consumers. Technological advancements such as 3D NAND with high layer counts and the emergence of QLC have enabled SSD capacities to increase substantially over the last few years. And with those economies of scale kicking in, multiple vendors are finally able to offer consumer-focused flash-based storage devices in capacities up to 4TB.

At the 2021 CES, Western Digital introduced 4TB variants of almost all their portable SSD families, including their flagship SanDisk Extreme PRO v2 and the WD_BLACK P50 lines. In March, Crucial updated its affordable X6 lineup to include a 4TB version. WDs flagships and Crucials mainstream X6 offerings represent two ends of the pricing spectrum. At the same capacity point, they present an interesting view of the tradeoffs involved in bringing a portable SSD to the market. Read on for an analysis of the performance and value propositions of the SanDisk Extreme PRO v2 and the Crucial X6 4TB portable SSDs.