Western Digital · Enterprise
WUH721818ALE6L4
Ultrastar DC HC550 18TB
SATA 6 Gb/s · 3.5-inch · CMR
Exact Amazon US product
$529.00
View on Amazon US ↗Used / renewed listing · ASIN B09RYLD7GL
Price as of Oct 17, 2026 11:44 UTC
The Western Digital WUH721818ALE6L4 is a 18TB Ultrastar DC HC550 hard drive for server and enterprise storage, using SATA 6 Gb/s in a 3.5-inch form factor.
Manufacturer specifications
| Model number | WUH721818ALE6L4 |
|---|---|
| Nominal capacity | 18 TB · 18000 GB |
| RPM | 7200 |
| Interface | SATA 6 Gb/s |
| Recording | CMR |
| Cache (MB) | 512 |
| Form factor | 3.5-inch |
| Sector format | 512e |
| Drive construction | Helium |
| Recording evidence | Manufacturer recording specification ↗ |
| Recording verified | 2026-10-02 |
| Power Disable Pin 3 | Not supported (legacy configuration) |
Source: Western Digital Ultrastar DC HC550 datasheet, pages 2. Reviewed 2026-09-07. Published specifications, not our benchmark results.
What the specifications mean
- CMR recording is specified for this exact model. Check enclosure support and workload limits before installing it in an array.
Before ordering
Match WUH721818ALE6L4, 18TB and SATA 6 Gb/s against the selected offer. Check your system’s exact-model compatibility list and the seller’s warranty and return terms.
Amazon US listings
Exact model matches on Amazon.com. A verified ASIN identifies the product; it does not guarantee current stock. Check the selected variant, condition and seller.
Amazon US · ASIN B09RYLD7GL
$529.00 · as of Oct 17, 2026 11:44 UTC
Amazon US · ASIN B09NP4Y2JC
$559.00 · as of Oct 17, 2026 10:53 UTC
Same-capacity alternatives with Amazon US links
These models share the drive type, interface class and capacity. Compare their specifications and your system requirements before choosing a replacement.
Toshiba · MG09
MG09ACA18TE
18TB · SATA 6 Gb/s · CMR
Compare with WUH721818ALE6L4 →View on Amazon US ↗ASIN B093Z5LFWD · Check price and conditionSeagate · IronWolf Pro
ST18000NE000
18TB · SATA 6 Gb/s · CMR
Specifications & offers →View on Amazon US ↗ASIN B0CZM957F3 · Check price and conditionSeagate · Exos X18
ST18000NM000J
18TB · SATA 6 Gb/s · CMR
Compare with WUH721818ALE6L4 →View on Amazon US ↗ASIN B08JV6PP9B · Check price and conditionWUH721818ALE6L4 questions answered
Is WUH721818ALE6L4 CMR or SMR?
The manufacturer lists CMR recording for WUH721818ALE6L4. Other models and capacities in the same family can differ.
What connection does WUH721818ALE6L4 need?
WUH721818ALE6L4 uses SATA 6 Gb/s and a 3.5-inch form factor. Match both with the computer, controller or enclosure. An M.2 slot, 2.5-inch bay and 3.5-inch bay are not interchangeable.
How much usable space does WUH721818ALE6L4 provide?
Its nominal capacity is 18000 GB, approximately 16763.8 GiB before formatting. The filesystem, reserved space and any RAID redundancy reduce usable capacity further.