Side-by-side: WD_BLACK SN850X 2TB ($199) vs WD_BLACK SN7100 4TB ($319). $/TB winner, specs, real-world picks for May 2026.
Both run on Gen 4 hardware but at different capacities: 2 TB for the WD_BLACK SN850X 2TB versus 4 TB for the WD_BLACK SN7100 4TB. Whether the larger drive's $/TB advantage justifies the higher upfront cost depends on how much you actually need.
Hardware-wise, the WD_BLACK SN850X 2TB runs on the proprietary WD G2 silicon, optimized for the WD_BLACK line. The WD_BLACK SN7100 4TB pairs an A101 controller that replaced the older WD designs in the SN7100 generation.
Prices favor the WD_BLACK SN7100 4TB by $19.75/TB ($79.75/TB versus $99.50/TB). Not a huge gap, but enough to be the tiebreaker if performance is similar.
The DRAM-vs-HMB question divides opinion: WD_BLACK SN850X 2TB's on-board DRAM theoretically helps under sustained workloads, while WD_BLACK SN7100 4TB's HMB approach has matured enough that most users won't see the difference. Pick on price if everything else is similar.
WD_BLACK SN7100 4TB earns higher TBW ratings (2,400 vs 1,200 TBW) — relevant for sustained write workloads, irrelevant for everything else.
For PS5 expansion, both are PCIe Gen 4 M.2 2280 drives that meet Sony's minimum spec (7,000 MB/s read). The console can't take advantage of speeds beyond that, so save money by choosing the WD_BLACK SN7100 4TB. Note for handheld gamers: M.2 2280 is the desktop/laptop standard. Steam Deck and the ROG Ally line need 2230 drives — neither WD_BLACK SN850X 2TB nor WD_BLACK SN7100 4TB fits without modification.
Go with the WD_BLACK SN850X 2TB for the lower retail price ($199 vs $319), and a dedicated DRAM cache chip. WD_BLACK's SN850X earned its reputation through consistent sustained performance under gaming workloads — fewer micro-stutters during open-world streaming than budget alternatives.
Go with the WD_BLACK SN7100 4TB for better $/TB economics ($79.75/TB), and a higher TBW endurance rating (2,400 TBW).