Drive comparison
ST12000NM004J vs ST12000NM008G
Seagate Exos X18 12TB and Seagate Exos X16 12TB, compared using published manufacturer specifications.
Seagate
Exos X18 12TB
ST12000NM004J
SAS 12 Gb/s · 3.5-inch
$405.00
Amazon US · Used / renewed listing ↗ASIN B09YRZ1JPC · as of Sep 12, 2026 04:48 UTC
Full specifications & all listings →Seagate
Exos X16 12TB
ST12000NM008G
SAS 12 Gb/s · 3.5-inch
No verified exact-model Amazon listing yet.
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?
- Sustained transfer (up to MB/s): ST12000NM004J lists 270; ST12000NM008G lists 233.
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 | ST12000NM004J | ST12000NM008G |
|---|---|---|
| Manufacturer | Seagate | Seagate |
| Product family | Exos X18 | Exos X16 |
| Model number | ST12000NM004J | ST12000NM008G |
| Capacity (TB) | 12 | 12 |
| RPM | 7200 | 7200 |
| Interface | SAS 12 Gb/s | SAS 12 Gb/s |
| Cache (MB) | 256 | 256 |
| Form factor | 3.5-inch | 3.5-inch |
| Average idle power (W) | 5 | 5 |
| Power-on hours per year | 8760 | 8760 |
| Manufacturer limited warranty | 5 years (eligible new drives) | 5 years (eligible new drives) |
| Sustained transfer (up to MB/s) | 270 | 233 |
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
ST12000NM004J
Seagate Exos X18 manufacturer specifications ↗ · pages 3
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.
ST12000NM008G
Seagate Exos X16 manufacturer specifications ↗ · pages 3
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.