Drive comparison
ST20000NTZ01 vs WD201KFGX
Seagate IronWolf Pro 20TB and Western Digital WD Red Pro 20TB, compared using published manufacturer specifications.
Seagate
IronWolf Pro 20TB
ST20000NTZ01
SATA 6 Gb/s · 3.5-inch
No verified exact-model Amazon listing yet.
Full specifications & all listings →
Western Digital
WD Red Pro 20TB
WD201KFGX
SATA 6Gb/s · 3.5-inch
$949.97
Amazon US · New listing ↗ASIN B09TBF6GHJ · as of Sep 12, 2026 04:49 UTC
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What differs between these models?
- Interface: ST20000NTZ01 lists SATA 6 Gb/s; WD201KFGX lists SATA 6Gb/s.
- Cache (MB): ST20000NTZ01 lists 256; WD201KFGX lists 512.
- Sustained transfer (up to MB/s): ST20000NTZ01 lists 285; WD201KFGX lists 268.
A larger cache, higher RPM or higher advertised sequential speed alone does not establish which drive is better for your workload.
Specifications side by side
| Specification | ST20000NTZ01 | WD201KFGX |
|---|---|---|
| Manufacturer | Seagate | Western Digital |
| Product family | IronWolf Pro | WD Red Pro |
| Model number | ST20000NTZ01 | WD201KFGX |
| Capacity (TB) | 20 | 20 |
| RPM | 7200 | 7200 |
| Interface | SATA 6 Gb/s | SATA 6Gb/s |
| Recording | CMR | CMR |
| Cache (MB) | 256 | 512 |
| Form factor | 3.5-inch | 3.5-inch |
| Power-on hours per year | 8760 | Not recorded |
| Workload rating (TB/year) | 550 | 550 |
| Average operating power (W) | 7.7 | Not recorded |
| Rotational vibration sensors | Yes | Not recorded |
| Manufacturer limited warranty | 5 years (eligible new drives) | 5 years (eligible new drives) |
| Sustained transfer (up to MB/s) | 285 | 268 |
| Physical sector size (bytes) | Not recorded | 4096 |
Compatibility and buying checks
- Compare new and renewed offers separately. The manufacturer specification does not guarantee the warranty or return policy of a marketplace seller.
Manufacturer sources
ST20000NTZ01
Seagate IronWolf Pro manufacturer specifications ↗ · pages 2
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.
WD201KFGX
Western Digital WD Red Pro manufacturer datasheet ↗
Reviewed 2026-08-21. Published specifications; no independent benchmark or failure-rate claim.