WD Blue SN5100 vs WD_BLACK SN850X at every capacity: prices, $/TB, speeds, endurance. Which to buy in July 2026 — full family comparison.
WD Blue SN5100 and WD_BLACK SN850X compete at every capacity where both are sold, so the real question isn't a single price tag — it's which family gives you more per terabyte at the capacity you actually need. The table below breaks that down.
Peak sequential read favors the WD_BLACK SN850X at 7,300 MB/s against 6,600 MB/s. For gaming and general desktop use the difference is imperceptible; for large-file work it's measurable.
The WD_BLACK SN850X family is the value pick — $133.75/TB at its cheapest configuration versus $182.00/TB for the WD Blue SN5100. The WD Blue SN5100 has to win on features (cache, endurance, brand support) to justify its premium.
The cache design differs: WD_BLACK SN850X carries on-board DRAM, WD Blue SN5100 borrows system RAM via HMB. This matters for database-style workloads and long video-editing sessions, not for everyday use.
| Capacity | WD Blue SN5100 | WD_BLACK SN850X | |
|---|---|---|---|
| 1 TB | $182 · $182.00/TB | $220 · $220.00/TB | Full comparison → |
| 2 TB | — | $348 · $174.00/TB | |
| 4 TB | — | $535 · $133.75/TB | |
| 8 TB | — | $1300 · $162.50/TB |