Drive comparison
ST18000NM000D vs ST18000NM005J
Seagate Exos X20 18TB and Seagate Exos X18 18TB, compared using published manufacturer specifications.
Seagate
Exos X20 18TB
ST18000NM000D
12 Gb/s SAS · 3.5-inch
$689.00
Amazon US · New listing ↗ASIN B09MWKFG51 · as of Sep 12, 2026 04:49 UTC
Full specifications & all listings →
Seagate
Exos X18 18TB
ST18000NM005J
SAS 12 Gb/s · 3.5-inch
$794.45
Amazon US · New listing ↗ASIN B098YCXY22 · as of Sep 12, 2026 11:42 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: ST18000NM000D lists 12 Gb/s SAS; ST18000NM005J lists SAS 12 Gb/s.
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 | ST18000NM000D | ST18000NM005J |
|---|---|---|
| Manufacturer | Seagate | Seagate |
| Product family | Exos X20 | Exos X18 |
| Model number | ST18000NM000D | ST18000NM005J |
| Capacity (TB) | 18 | 18 |
| FIPS | No | Not recorded |
| Interface | 12 Gb/s SAS | SAS 12 Gb/s |
| Form factor | 3.5-inch | 3.5-inch |
| Manufacturer limited warranty | 5 years (eligible new drives) | 5 years (eligible new drives) |
| RPM | Not recorded | 7200 |
| Cache (MB) | Not recorded | 256 |
| Average idle power (W) | Not recorded | 5.6 |
| Power-on hours per year | Not recorded | 8760 |
| Sustained transfer (up to MB/s) | Not recorded | 270 |
Compatibility and buying checks
- A SAS drive requires a compatible SAS controller or backplane. A normal motherboard SATA port cannot operate a SAS drive.
- Compare new and renewed offers separately. The manufacturer specification does not guarantee the warranty or return policy of a marketplace seller.
Manufacturer sources
ST18000NM000D
Seagate Exos X20 manufacturer specifications ↗
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.
ST18000NM005J
Seagate Exos X18 manufacturer specifications ↗ · pages 2
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.