WD20EFAX - CMR or SMR?

SMR

The WD Red 2TB (WD20EFAX) uses SMR recording.

Live rankings this model belongs to: every 2TB hard drive. Product pages for this part number: WD Red 2TB WD20EFAX.

Verified against: WD Red NAS HDD product brief · Checked

Sources disagree on this model

WD's own Red product brief prints SMR against this model, footnoted as device-managed SMR. This is one of the four capacities at the centre of the 2020 episode.

What this means for you

Shingled recording overlaps tracks like roof tiles to raise density. Reading is unaffected, and for sequential work, archives, media libraries, backup targets, files written once and read many times, this drive is genuinely fine and the saving is real. The problem is sustained random writing, because modifying data under an existing track can force the tracks above it to be rewritten too. A RAID rebuild or a ZFS resilver is hours of exactly that pattern with no idle time to recover, so a 2TB WD20EFAX in an array can extend a rebuild dramatically, and the rebuild window is precisely when the array has no redundancy left. Do not put this drive in a NAS or a parity array.

Specifications

Model numberWD20EFAX
BrandWD
FamilyWD Red
Capacity2TB
Form factor3.5"
Rotational speed5400 RPM
Cache256 MB
Recording technologySMR
Workload rate180 TB/year
Warranty3 years
StatusCurrent
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.

We track this drive - live price
WD Red 2TB WD20EFAX
$219.90 · $109.95/TB
Buy on AmazonPrice history →

Need CMR at this capacity?

If this drive is going into an array, a NAS, or anything that rebuilds, shingled recording is the wrong choice at any price. These are conventionally-recorded drives at this capacity or one step up, in stock right now with live prices.

DriveCapacityRecording$/TBPrice
SkyHawk 3TB ST3000VX0093TBCMR$50.00$150Buy on Amazon
Red Pro 10TB NAS WD103KFBX10TBCMR$45.00$450Buy on Amazon
WD Red Pro 12TB WD121KFBX12TBCMR$29.17$350Buy on Amazon

Verified CMR model numbers at this size: WD2002FFSX, WD23PURZ, WD20EFPX, ST3000VX009.

Related models

Other WD Red capacities
WD30EFAX3TBSMRWD40EFAX4TBSMRWD60EFAX6TBSMRWD80EFAX8TBCMR · familyWD100EFAX10TBCMR · familyWD120EFAX12TBCMR · family
The same capacity from other makers
ST2000DM0062TB—ST2000DX0022TBCMR · familyST2000VX0082TBCMR · family
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Frequently asked questions

Is the WD20EFAX CMR or SMR?

It is SMR, per WD Red NAS HDD product brief - WD's documentation for this exact part number - which also rates it at 180TB/year workload; the page's cheapest in-stock conventional pick right now is the SkyHawk 3TB ST3000VX009.

Can I use the WD20EFAX in a NAS or RAID array?

We would not: WD Red NAS HDD product brief states SMR for the WD20EFAX, and shingled recording turns a rebuild into hours of the write pattern it handles worst. The page's own in-stock conventional alternative right now is the SkyHawk 3TB ST3000VX009. For sequential and archival use outside an array this drive is fine.

What should I buy instead of the WD20EFAX for a NAS?

A conventionally-recorded drive at 2TB or one step up - right now the table's top in-stock pick is the SkyHawk 3TB ST3000VX009. Every model number linked in the table has its own verified page with the manufacturer source.

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