Drive comparison
ST18000VN000 vs WD181KFGX
Seagate IronWolf 18TB and Western Digital WD Red Pro 18TB, compared using published manufacturer specifications.
Seagate
IronWolf 18TB
ST18000VN000
SATA 6 Gb/s · 3.5-inch
$844.45
Amazon US · New listing ↗ASIN B0BJPPGTX4 · as of Sep 12, 2026 10:53 UTC
Full specifications & all listings →
Western Digital
WD Red Pro 18TB
WD181KFGX
SATA 6Gb/s · 3.5-inch
$544.00
Amazon US · Used / renewed listing ↗ASIN B09CN2CBH8 · as of Sep 12, 2026 10:56 UTC
Full specifications & all listings →As an Amazon Associate I earn from qualifying purchases. Match the selected variant, condition and seller terms before ordering.
What differs between these models?
- Interface: ST18000VN000 lists SATA 6 Gb/s; WD181KFGX lists SATA 6Gb/s.
- Cache (MB): ST18000VN000 lists 256; WD181KFGX lists 512.
- Workload rating (TB/year): ST18000VN000 lists 180; WD181KFGX lists 550.
- Manufacturer limited warranty: ST18000VN000 lists 3 years (eligible new drives); WD181KFGX lists 5 years (eligible new drives).
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 | ST18000VN000 | WD181KFGX |
|---|---|---|
| Manufacturer | Seagate | Western Digital |
| Product family | IronWolf | WD Red Pro |
| Model number | ST18000VN000 | WD181KFGX |
| Capacity (TB) | 18 | 18 |
| RPM | 7200 | 7200 |
| NAS bays | Up to 8 | Not recorded |
| Interface | SATA 6 Gb/s | SATA 6Gb/s |
| Recording | CMR | CMR |
| Cache (MB) | 256 | 512 |
| Form factor | 3.5-inch | 3.5-inch |
| Workload rating (TB/year) | 180 | 550 |
| Manufacturer limited warranty | 3 years (eligible new drives) | 5 years (eligible new drives) |
| Physical sector size (bytes) | Not recorded | 4096 |
| Sustained transfer (up to MB/s) | Not recorded | 272 |
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
ST18000VN000
Seagate IronWolf datasheet DS1904-20 ↗ · pages 2–3
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.
WD181KFGX
Western Digital WD Red Pro manufacturer datasheet ↗
Reviewed 2026-08-21. Published specifications; no independent benchmark or failure-rate claim.