WD4003FFBX - CMR or SMR?

CMR

The WD WD Red Pro 4TB (WD4003FFBX) uses CMR recording.

Verified against: WD Red Pro NAS hard drive product page ยท Checked

What this means for you

Conventional recording writes tracks side by side without overlap, so a write never forces the drive to rewrite neighbouring data. That makes the WD4003FFBX 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.

Specifications

Model numberWD4003FFBX
BrandWD
FamilyWD Red Pro
Capacity4TB
Form factor3.5"
Rotational speed7200 RPM
Cache256 MB
Recording technologyCMR
Workload rate300 TB/year
Warranty5 years
StatusCurrent
Replaced byโ€”

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.

Related models

Other WD Red Pro capacities
WD2002FFSX2TBCMRWD6003FFBX6TBCMRWD8003FFBX8TBCMRWD101KFBX10TBCMRWD121KFBX12TBCMRWD141KFGX14TBCMRWD161KFGX16TBCMRWD181KFGX18TBCMRWD201KFGX20TBCMRWD221KFGX22TBCMRWD240KFGX24TBCMRWD260KFGX26TBCMR
The same capacity from other makers
ST4000VX0074TBCMRST4000VX0164TBCMRST4000VN0064TBCMR
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Frequently asked questions

Is the WD4003FFBX CMR or SMR?

It is CMR. That comes from WD Red Pro NAS hard drive product page, which is WD's own documentation for this exact part number rather than a capacity-level summary or a retailer listing.

Can I use the WD4003FFBX in a NAS or RAID array?

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.

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