Seagate documents CMR for the IronWolf family; this part number is not named individually. The answer comes from Seagate IronWolf NAS hard drive product page, which states it at FAMILY level - it does not name this part number. Families can ship mixed recording technologies, so this is the family's answer, not a verified answer for this exact drive.
ST - Seagate product prefix. (Seagate - product part-number and model-number decoding)4000 - Capacity field. 4000 denotes 4TB of formatted capacity. (Seagate - product part-number and model-number decoding)VN - IronWolf NAS family. (Seagate - product part-number and model-number decoding)006 - we have not found a Seagate document defining this segmentNearest model with a sourced answer: ST4000VX007 (Seagate SkyHawk 4TB, CMR). Listed for comparison only - two part numbers can use different recording methods, so its answer is not ST4000VN006's.
Part-number reference: ST4000VN006 — decoded segments, sibling variants and the warranty check. Live rankings this model belongs to: every 4TB hard drive. Product pages for this part number: Seagate IronWolf 4TB NAS (no current offer) · Seagate IronWolf 4TB NAS ST4000VN006 (no current offer).
Family-level source (states it for the family, does not name this part number): Seagate IronWolf NAS hard drive product page · Checked
Seagate documents CMR for the IronWolf family; this part number is not named individually. That is useful evidence and it is not verification: a family can ship more than one recording method - WD Red is the standing example - so for a NAS or anything that rebuilds, prefer a drive whose own part number is documented. For a single drive holding replaceable data the distinction is largely academic.
| Model number | ST4000VN006 |
| Brand | Seagate |
| Family | IronWolf |
| Capacity | 4TB |
| Form factor | 3.5" |
| Rotational speed | — |
| Cache | 256 MB |
| Recording technology | CMR (family level - part number not named) |
| Workload rate | 180 TB/year |
| Warranty | 3 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.
Seagate documents CMR for the IronWolf family; this part number is not named individually. So the family answer is CMR, from Seagate IronWolf NAS hard drive product page; we have not found a document that names this exact part number.
The recording technology is unsourced, so we cannot clear it for arrays either way. What the spec table does say: a 180TB/year workload rating, which is NAS-or-higher class duty and a 3-year warranty. For an array, prefer a 4TB drive whose recording technology is sourced, such as the ST4000VX007 (CMR).