Drive comparison
ST18000NM000J vs HDWG81JXZSTB
Seagate Exos X18 18TB and Toshiba N300 Pro 18TB, compared using published manufacturer specifications.
Seagate
Exos X18 18TB
ST18000NM000J
SATA 6 Gb/s · 3.5-inch
$725.91
Amazon US · New listing ↗ASIN B08JV6PP9B · as of Sep 12, 2026 11:43 UTC
Full specifications & all listings →Toshiba
N300 Pro 18TB
HDWG81JXZSTB
SATA 6 Gb/s · 3.5-inch
No verified exact-model Amazon listing yet.
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What differs between these models?
- Cache (MB): ST18000NM000J lists 256; HDWG81JXZSTB lists 1024.
- Sustained transfer (up to MB/s): ST18000NM000J lists 270; HDWG81JXZSTB lists 294.
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 | ST18000NM000J | HDWG81JXZSTB |
|---|---|---|
| Manufacturer | Seagate | Toshiba |
| Product family | Exos X18 | N300 Pro |
| Model number | ST18000NM000J | HDWG81JXZSTB |
| Capacity (TB) | 18 | 18 |
| RPM | 7200 | 7200 |
| Interface | SATA 6 Gb/s | SATA 6 Gb/s |
| Cache (MB) | 256 | 1024 |
| Form factor | 3.5-inch | 3.5-inch |
| Average idle power (W) | 5.3 | Not recorded |
| Power-on hours per year | 8760 | Not recorded |
| Manufacturer limited warranty | 5 years (eligible new drives) | 5 years (eligible new drives) |
| Sustained transfer (up to MB/s) | 270 | 294 |
| NAS bays | Not recorded | 24 |
| Recording | Not recorded | CMR |
| Sector format | Not recorded | 512e |
| Idle power (W) | Not recorded | 4.16 |
| Package / region | Not recorded | US retail; manufacturer-documented bulk package alias |
| Workload rating (TB/year) | Not recorded | 550 |
| Average operating power (W) | Not recorded | 7.41 |
| Rotational vibration sensors | Not recorded | Yes |
Compatibility and buying checks
- Check sector-format support in the controller and operating system, particularly for native 4K (4Kn) variants.
- Compare new and renewed offers separately. The manufacturer specification does not guarantee the warranty or return policy of a marketplace seller.
Manufacturer sources
ST18000NM000J
Seagate Exos X18 manufacturer specifications ↗ · pages 2
Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.
HDWG81JXZSTB
Toshiba N300 Pro US datasheet TAEC-2839-R2.0, July 2026 ↗ · pages 4, 7
Reviewed 2026-09-08. Published specifications; no independent benchmark or failure-rate claim.