WD Ultrastar DC HC570 22TB
22TB
Model WUH722222ALE6L4
- rpm
- 7,200
- MB cache
- 512
- TB/yr
- 550
- yr warranty
- 5
WD Ultrastar DC HC570 range
Should you buy the WD Ultrastar DC HC570 22 TB?
It's at home in a rack or a garage, where 7,200 rpm of spinning rust can whirr away all day without bothering anyone. WD backs it for five years, which is a long time in drive terms. It's also one of the better performers in Backblaze's data, with a lifetime AFR of 0.58% and an interval that stays under the 1.40% median. It's CMR, which is what you want anywhere near a RAID or ZFS rebuild.
Watch out for
Being 7,200 rpm, it's in the noisier, warmer class of drive, and you'll want it somewhere you don't sit.
A 4-bay box full of these gives 66 TB after one drive's worth of parity.
Specifications
Each value links to the Western Digital page or datasheet it came from, and "Not published" means the maker doesn't list it there.
| Capacity | 22 TB | source for Capacity (documents.westerndigital.com, opens in new tab) |
|---|---|---|
| Spindle speed | 7,200 rpm | source for Spindle speed (documents.westerndigital.com, opens in new tab) |
| Recording technology | CMR | source for Recording technology (documents.westerndigital.com, opens in new tab) |
| Cache | 512 MB | source for Cache (documents.westerndigital.com, opens in new tab) |
| Interface | SATA 6Gb/s | source for Interface (documents.westerndigital.com, opens in new tab) |
| Form factor | 3.5in | source for Form factor (documents.westerndigital.com, opens in new tab) |
| Workload rating | 550 TB/yr | source for Workload rating (documents.westerndigital.com, opens in new tab) |
| MTBF / MTTF | 2,500,000 hours | source for MTBF / MTTF (documents.westerndigital.com, opens in new tab) |
| Warranty | 5 years | source for Warranty (documents.westerndigital.com, opens in new tab) |
Sources: documents.westerndigital.com
Failure rate
Backblaze runs 45,556 of these (WDC WUH722222ALE6L4) in its data centres, and over 72,927 drive-years 423 have failed, an annualised failure rate of 0.58%. The 95% interval runs from 0.53% to 0.64%, and the whole of that sits below the 1.40% median.
Lifetime72,927 drive-yrs 0.58%0.53–0.64
2025 Q338,963 drives 0.51%0.38–0.68
2025 Q444,265 drives 0.23%0.15–0.34
2026 Q145,501 drives 0.38%0.28–0.52
2026 Q245,556 drives 0.56%0.43–0.71
Median lifetime AFR across Backblaze drive models: 1.40%
Source: Backblaze Drive Stats, lifetime to 2026 Q2. Bear in mind that's data-centre use, which is a lot harder on a drive than a home NAS will ever be.
WD Ultrastar DC HC570 22TBWUH722222ALE6L4