WD_BLACK SN7100 vs WD_BLACK SN850X at every capacity: prices, $/TB, speeds, endurance. Which to buy in September 2026 — full family comparison.
Comparing WD_BLACK SN7100 against WD_BLACK SN850X model-to-model means looking across the whole capacity range: the winner at 1 TB isn't always the winner at 4 TB, because per-TB pricing shifts with capacity. Here's the full picture.
The WD_BLACK SN850X posts the higher sequential read spec (7,300 MB/s vs 7,000 MB/s). Whether that shows up for you depends on workload: game load times won't change, sustained transfers will.
On value, the WD_BLACK SN7100 family wins at most capacities — its best configuration lands at $142.25/TB versus $164.75/TB for the WD_BLACK SN850X's best. During the 2026 NAND shortage that spread compounds quickly at 2-4 TB.
Architecturally, the WD_BLACK SN850X family uses a dedicated DRAM cache while the WD_BLACK SN7100 relies on HMB (Host Memory Buffer). For OS and gaming duty they behave identically; sustained random writes favor DRAM.
| Capacity | WD_BLACK SN7100 | WD_BLACK SN850X | |
|---|---|---|---|
| 1 TB | — | $249 · $249.00/TB | |
| 2 TB | $305 · $152.50/TB | $390 · $195.00/TB | Full comparison → |
| 4 TB | $569 · $142.25/TB | $659 · $164.75/TB | Full comparison → |
| 8 TB | — | $1598 · $199.75/TB |