The Seagate IronWolf Pro 20TB (ST20000NT001) uses CMR recording.
Part-number reference: ST20000NT001 — decoded segments, sibling variants and the warranty check. Live rankings this model belongs to: every 20TB hard drive. Product pages for this part number: Seagate IronWolf Pro 20TB NAS.
Verified against: Seagate IronWolf Pro 3.5 HDD Data Sheet DS2129.4-2311US · Checked
Conventional recording writes tracks side by side without overlap, so a write never forces the drive to rewrite neighbouring data. That makes the ST20000NT001 safe for every use including RAID, ZFS, a NAS, and anything with sustained random writes. A rebuild or a resilver on this drive behaves the way the array expects, which is the whole reason the distinction matters. There is no recording-technology reason to avoid this drive for any workload.
| Model number | ST20000NT001 |
| Brand | Seagate |
| Family | IronWolf Pro |
| Capacity | 20TB |
| Form factor | 3.5" |
| Rotational speed | 7200 RPM |
| Cache | 256 MB |
| Recording technology | CMR |
| Workload rate | 550 TB/year |
| Warranty | 5 years |
| Status | Current |
| Replaced by | — |
A dash means we have not found a manufacturer document stating that field for this exact model. We leave it blank rather than filling it from a retailer listing.
It is CMR, per Seagate IronWolf Pro 3.5 HDD Data Sheet DS2129.4-2311US - Seagate's documentation for this exact part number - which also rates it at 550TB/year workload; its closest tracked rival at this capacity is the WD201KFGX.
Yes: Seagate IronWolf Pro 3.5 HDD Data Sheet DS2129.4-2311US states CMR for the ST20000NT001, and conventional recording means a write never forces neighbouring tracks to be rewritten, so rebuilds and resilvers behave normally. Check the workload rating and warranty for your duty cycle separately.