Seagate
Seagate Exos X18 ST18000NM004JProduct 18 TB SAS 12Gb/s 3.5" internal hard drive
An 18 TB SAS 12Gb/s 3.5" internal hard drive with 7200 RPM spindle speed and 256 MB cache for storage and surveillance systems
- InterfaceSAS 12Gb/s
- Capacity18TB
- NAND Flash Memory TypeSLC
- RPM7200 RPM
- Cache256MB
- Form Factor3.5"
- 18 TB capacity for massive data storage
- SAS 12Gb/s interface delivers high throughput
- 7200 RPM spindle speed enables fast access
- 256 MB cache buffers heavy workloads
- Hot-pluggable 3.5" design simplifies drive replacement
Exos X18 18 TB SAS enterprise drive
The Seagate Exos X18 ST18000NM004J is an 18 TB internal hard drive built for storage systems and video surveillance deployments. It runs at 7200 RPM with a 256 MB cache and uses a 512e/4Kn disk format. The 3.5-inch form factor fits standard enterprise bays and the drive is hot-pluggable for service without downtime.
Who this suits and who should look elsewhere
This drive suits operators who need high-capacity nearline storage on a 12Gb/s SAS fabric with hot-plug support. It is not for systems that lack SAS backplane or controller infrastructure, nor for workloads that demand solid-state latency or a different physical interface.
Deciding specification — 12Gb/s SAS interface
The single specification that decides fit is the 12Gb/s SAS interface, which requires a compatible SAS HBA, RAID controller or backplane to operate. Without that host-side support the drive cannot be connected or used.
Highlights
- 18 TB capacity for massive data storage
- SAS 12Gb/s interface delivers high throughput
- 7200 RPM spindle speed enables fast access
- 256 MB cache buffers heavy workloads
- Hot-pluggable 3.5" design simplifies drive replacement
Specifications
| Brand | Seagate |
|---|---|
| Part Number | ST18000NM004J |
| Interface | SAS 12Gb/s |
| Capacity | 18TB |
| NAND Flash Memory Type | SLC |
| RPM | 7200 RPM |
| Cache | 256MB |
| Form Factor | 3.5" |
Questions about this item
What are the exact height, width and depth measurements for the 3.5" Exos X18 drive?
The drive measures 1" high, 4" wide and 5.8" deep, fitting standard 3.5" internal bays.
Does the SAS 12Gb/s interface support hot-plug insertion, and what is the common mistake?
Yes, the drive is hot-pluggable; the common error is inserting it into a backplane that only supports 6Gb/s SAS, which limits speed.
When should the 256 MB cache and 7200 RPM spindle be monitored for replacement?
Monitor SMART attributes for reallocated sectors or rising seek errors; replace the drive if either trend accelerates.
New to this? Paying with USDT: TRC-20 or ERC-20 — what to check, what it costs to pay, and what is never asked for.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.



