WD_BLACK SN7100 vs WD_BLACK SN850X at every capacity: prices, $/TB, speeds, endurance. Which to buy in July 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 SN850X family wins at most capacities — its best configuration lands at $133.75/TB versus $142.50/TB for the WD_BLACK SN7100'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 | — | $220 · $220.00/TB | |
| 2 TB | $290 · $145.00/TB | $348 · $174.00/TB | Full comparison → |
| 4 TB | $570 · $142.50/TB | $535 · $133.75/TB | Full comparison → |
| 8 TB | — | $1300 · $162.50/TB |