WD Red Pro 24TB: WD240KFGX vs WD241KFGX, and the 24TB Alternatives

WD Red Pro 24TB price on Amazon.co.uk

The table lists Amazon.co.uk offers for WD240KFGX and WD241KFGX that are in stock right now. It holds 2 listings. Prices are pounds sterling inc VAT, and each row prints whether the offer is new or used. When the table is short, the alternatives table beneath it fills in with other 24TB NAS and enterprise drives, each row labelled with why it is there.

Read the model number on any 24TB Red Pro listing before you buy. The two drives share a capacity and a name, but WD's own sheet gives them different noise, power and temperature figures, set out in the next section.

In-stock alternatives

None of these is the product this page covers: they are what is in stock on Amazon.co.uk beside it right now. Each row says why it is listed. Check the interface, form factor and part number against your system before buying.

WD Red Pro 24TB WD240KFGX or WD241KFGX: what differs

The two numbers trade noise against power. WD240KFGX is the quieter drive at idle by 5 dBA on WD's sheet, which matters most in a NAS that shares a room with people. WD241KFGX draws 0.3 W less at idle and 0.4 W less in read/write. Across a four-bay array idling all day, that is 1.2 W in WD241KFGX's favour on WD's figures, a small sum either way.

The temperature row matters at the cold end only. WD240KFGX is rated to operate from 0°C, WD241KFGX from 5°C, and both to 65°C. A NAS in an unheated garage or outbuilding through a cold winter is the case where that 5°C floor could come into play. In a heated room it makes no difference.

On the same sheet, WD241KFGX prints the same idle noise, idle power, read/write power and temperature range as the 26TB WD260KFGX, while WD240KFGX's figures are its own. We draw no conclusion from that about how the drives are built; it is simply how the columns read.

What every WD Red Pro 24TB NAS hard drive shares

• CMR recording, listed for every model from 18TB to 26TB.
• Helium, at every model in that table.
• OptiNAND, marked Yes for both 24TB models.
• 512MB cache.
• A 550TB-per-year workload rating.
• A 5-year limited warranty and an MTBF of 2,500,000 hours.

WD positions Red Pro for RAID-optimised NAS systems with an unlimited number of bays, so neither 24TB model comes with a bay ceiling on WD's sheet. The warranty figure is WD's, printed on its data sheet; what a seller's listing carries is a separate matter, and worth reading before you click Buy on Amazon, more so on a used offer.

WD Red Pro 24TB against 24TB enterprise and NAS drives

This second table lists 24TB SATA drives from the Exos, Ultrastar and Toshiba MG lines, new and used. It holds 1 listing right now. These are the drives a Red Pro 24TB buyer is most likely to weigh it against, and on workload the sheets put them close together.

The acoustics column is not one scale. WD prints dBA for Red Pro, Seagate's Exos X24 manual and WD's HC580 sheet print sound power in bels, and Toshiba prints dB for MG11. We label each figure in the unit its maker uses and do not convert between them or rank across them.

Two NAS drives fill the alternatives table when the Red Pro is short. Seagate's IronWolf Pro data sheet lists its 24TB model as ST24000NT002 and prints 20 dBA idle for it, measured in Seagate's Idle 1 state. Synology's Enterprise Series sheet lists HAT5320-24T at 24TB and rates the series at 550TB transferred per year. Neither is a Red Pro, and the alternatives table labels each row with the reason it is there.

Which WD Red Pro 24TB to buy

• For a NAS in a room you work or sleep in: WD240KFGX, at 20 dBA idle.
• For a NAS in a cupboard or rack where watts count more than decibels: WD241KFGX, at 3.6 W idle.
• For an unheated space that can drop below 5°C: WD240KFGX, rated from 0°C.

If neither is in stock, compare the alternatives on price per terabyte first and then on the maker's ratings, reading each in its own unit. Before you fix the number of drives, the RAID calculator below shows how much usable space a set of 24TB drives leaves under each RAID level.