It's a close match. Both components tie in most comparable specs (1 ties out of 5 specs).
| Spec | SeagateIronWolf 4TB | Western DigitalWD Black SN850X 2TB |
|---|---|---|
| Storage | ||
| Capacity | 4000 GB+100% | 2000 GB |
| Type | HDD | NVMe SSD |
| Interface | SATA 6 Gb/s | PCIe Gen4 x4 |
| Form Factor | 3.5" | M.2-2280 |
| NAND Type | N/A | TLC |
| Performance | ||
| Sequential Read | 195 MB/s | 7,300 MB/s+3644% |
| Sequential Write | ||
| 195 MB/s |
| 6,600 MB/s+3285% |
| Endurance (TBW) | N/A | 1,200 |
| Features | ||
| DRAM Cache | Yes | Yes |
| Platform | ||
| Controller | N/A | WD in-house |
| PCIe Gen | N/A | 4 |
| Price | ||
| MSRP | $100−29% | $140 |
| Release Date | Jan 2018 | Aug 2022 |
