The WD WD Red Plus 4TB (WD40EFZX) uses CMR recording.
Verified against: WD Red Plus HDD product brief ยท Checked
Conventional recording writes tracks side by side without overlap, so a write never forces the drive to rewrite neighbouring data. That makes the WD40EFZX 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 | WD40EFZX |
| Brand | WD |
| Family | WD Red Plus |
| Capacity | 4TB |
| Form factor | 3.5" |
| Rotational speed | 5400 RPM |
| Cache | 128 MB |
| Recording technology | CMR |
| Workload rate | 180 TB/year |
| Warranty | 3 years |
| Status | Current |
| Replaced by | โ |
A dash means the manufacturer does not state that field for this exact model. We leave it blank rather than filling it from a retailer listing.
It is CMR. That comes from WD Red Plus HDD product brief, which is WD's own documentation for this exact part number rather than a capacity-level summary or a retailer listing.
Yes. Conventional recording means a write never forces neighbouring tracks to be rewritten, so rebuilds and resilvers behave normally. There is no recording-technology objection to this drive in an array, check the workload rating and warranty for your duty cycle separately.