WD Red Pro: The NAS Drive WD Calls Enterprise-Class, Model by Model

WD Red Pro price on Amazon.co.uk

Every WD Red Pro listing we track on Amazon.co.uk is in this table, from the 2TB model to 26TB, sorted by price per terabyte. Prices are pounds sterling inc VAT, and each row prints whether the offer is new or used. It holds 23 listings right now. Lowest price per TB: £42.10/TB. The 24TB drives have their own page, WD Red Pro 24TB, which compares the two 24TB model numbers in detail.

Most Red Pro listings give a WD model number such as WD161KFGX or WD8003FFBX. Some carry a retail code instead, beginning WDBC9Y or WDBRJY. Those codes are not on the part-number list in WD's data sheet, so such a listing cannot be tied to a row of the sheet, and the table does not print a recording technology for it. Ask the seller for the model number on the drive label if the code is all the listing gives.

Is WD Red Pro an enterprise drive? The ratings side by side

WD answers this itself. Its Red Pro data sheet opens by describing "enterprise-class hard drives", and positions them for RAID-optimised NAS systems with an unlimited number of bays. The ratings in the sheet's table for 18TB to 26TB bear that out when they are set beside enterprise data sheets.

On those three lines the NAS badge and the enterprise label say the same thing. That does not make a Red Pro and an Ultrastar the same product, and we make no claim about what else differs between them. It does mean that a buyer who wants enterprise ratings in a NAS can read Red Pro and the enterprise lines as one shortlist, and let price per terabyte, noise and the exact model number decide.

The same 18TB to 26TB table lists CMR recording and helium at every one of its seven models, so there is no SMR model to avoid in that range.

WD Red Pro 18TB, 20TB and 22TB to 26TB: OptiNAND, power and noise

The first thing that separates the big Red Pro models is OptiNAND. WD describes it as a proprietary technology that uses integrated iNAND embedded flash to perform key housekeeping functions, freeing up more capacity and improving overall drive performance. The sheet is not consistent about which drives have it. Its prose names the 22TB, 24TB and 26TB drives. Its specification table marks Yes for those and for both 20TB models, WD202KFGX and WD201KFGX, and No for the 18TB WD181KFGX. We print both and do not choose between them: if OptiNAND decides a 20TB purchase for you, ask WD or the seller to confirm it for that model number.

The second is noise. The 18TB is the loudest of the seven in average seek, at 36 dBA against 32 dBA for the rest. At the top, WD260KFGX and WD241KFGX idle at 25 dBA, while WD240KFGX and everything from 22TB down idle at 20 dBA.

Two capacities have two model numbers each, and in both cases the pair differ. At 24TB, WD241KFGX and WD240KFGX are 5 dBA apart at idle. At 20TB the acoustics match, but the sheet's performance and power rows do not: WD202KFGX lists a maximum internal transfer rate of 285MB/s, 6.1 W in read/write and 3.6 W at idle, while WD201KFGX lists 268MB/s, 6.9 W and 3.8 W. On WD's figures WD202KFGX is the faster and more frugal 20TB, so read the full model number in a listing rather than the capacity alone.

WD Red Pro 10TB to 16TB: where the model number decides the noise

This is the part of the range where the model number matters most. Three models, WD122KFBX, WD103KFBX and WD102KFBX, idle at 34 dBA, which is 14 dBA above the 20 dBA of the 14TB and 16TB drives. At 12TB the two model numbers sit on opposite sides of that gap: WD121KFBX idles at 20 dBA, WD122KFBX at 34 dBA. At 10TB both models read 34 dBA, so there is no quiet 10TB Red Pro on this sheet.

If the NAS shares a room with people, 14TB is the smallest capacity at which both Red Pro model numbers idle at 20 dBA, with WD121KFBX the single quiet model below it. If the box lives in a cupboard or a rack, the noise rows matter less and price per terabyte can lead.

WD Red Pro 2TB to 8TB: the FFBX and FFSX models

The smallest Red Pro drives sit in the sheet's last table under a different numbering: WD8005FFBX and WD8003FFBX at 8TB, WD6005FFBX and WD6003FFBX at 6TB, WD4005FFBX and WD4003FFBX at 4TB, and WD2002FFSX at 2TB. Every one of them idles at 29 dBA on WD's sheet, and average seek reads 36 dBA except at 2TB, where it is 31 dBA.

So a 4TB or 8TB Red Pro is quieter at idle than the 34 dBA models at 10TB and 12TB, and louder than the models from 14TB up, which idle at 20 or 25 dBA. Each of 4TB, 6TB and 8TB carries two model numbers ending 005 and 003, and on acoustics the sheet does not separate them. If a seller offers one in place of the other, check the full model number against WD's sheet before you buy.

WD Red Pro 16TB or a 16TB enterprise hard drive?

Sixteen terabytes is where Red Pro and the enterprise lines overlap most directly. The table above lists new 16TB SATA drives from Exos, Ultrastar and Toshiba MG. It holds 3 listings right now. Lowest price per TB: £23.04/TB, against £42.10/TB for the whole Red Pro table, which mixes every capacity.

Seagate's Exos X16 sheet, which covers 10TB to 16TB, states a 5-year limited warranty and a 2.5 million hour MTBF. Toshiba's MG10 overview covers 16TB, 18TB and 20TB and rates the series at 550TB per year. On WD's sheet the 16TB Red Pro, WD161KFGX, idles at 20 dBA with 36 dBA in seek, and the Red Pro's 550TB-per-year and 5-year figures are printed in the table for its 18TB to 26TB models.

The warranties above are manufacturers' warranties, printed on their data sheets. What a seller's listing carries is a separate matter, and a used row in particular deserves a careful read before you click Buy on Amazon. If your NAS is small and you are not after enterprise ratings, WD Red Plus is WD's other NAS line and has its own page.

How many WD Red Pro drives for the space you need

Red Pro runs from 2TB to 26TB, so the same usable space can come from fewer large drives or more small ones. The RAID calculator below shows what a given number of drives leaves after parity under each RAID level, which is worth settling before you pick a row from the table.