Seagate Exos vs WD Red Plus and Red Pro: Noise, Idle Watts and Ratings by Part Number

Exos vs WD Red: first decide which Red you mean

This page sets Exos against two of WD's Red NAS lines, Red Plus and Red Pro, and they sit in different places. Red Plus is aimed at RAID NAS systems of up to 8 bays, on a sheet running from 2 TB to 12 TB. Red Pro is the higher line, on a sheet running from 2 TB to 26 TB. Both WD sheets state CMR on every model, as Seagate's X24 sheet does for its models.

So Red Pro and Exos X24 meet on the two ratings buyers ask about most: 5 years of limited warranty, and a workload ceiling around 550TB a year, which Seagate's X24 manual counts as terabytes per 8,760 power-on hours. Red Plus sits apart, with 180TB a year and 3 years. One wrinkle on the Red Pro sheet: the 12 TB and 10 TB KFBX models carry 2,000,000 hours MTBF where the larger models carry 2,500,000.

Exos vs WD Red noise: the answer changes with the part number

WD's own Red models disagree with each other by a wide margin, which matters more for a desk-side NAS than any maker-to-maker comparison. Both Red sheets print idle and average seek in dBA. Seagate's Exos numbers are in bels, from its product manuals, where the X24 manual describes them as A-weighted sound power, measured overall with no pure tones.

Inside WD's sheets the reading is clear. At 12 TB, WD120EFBX idles at 20 dBA and WD120EFGX at 34 dBA, a 14 dBA gap between two drives sold as Red Plus 12TB. Red Pro repeats the split at 12 TB, WD121KFBX at 20 dBA and WD122KFBX at 34. At 10 TB every Red model on both sheets prints 34 dBA idle, while at 16 TB and 20 TB the Red Pro models print 20. If a quiet NAS matters to you, the part number on the listing matters more than the colour of the label.

Across makers the reading stops. We have not found a document that states what quantity WD's dBA figures measure, or one that converts Seagate's bels into dBA. Every Exos row above carries the same 2.8 and 3.2 bels, so on paper Exos has no quiet model and loud model the way Red does; what it cannot have is a ranking against WD.

We do not convert 2.8 bels to 28 dBA. Seagate's figure is a defined sound power level, and we have not found the method behind WD's dBA. Setting one beside the other as if they were one scale would be a guess presented as a measurement.

Seagate Exos vs WD Red idle power at 10TB to 20TB

Both WD sheets give idle watts per model, and at 10 TB and 12 TB they follow the noise split: the drives that idle quietly also idle on fewer watts. Seagate prints Idle A average and WD prints idle, each with its own footnote, so read each figure as its maker's own.

The lowest idle figure on this page belongs to a Red Pro, not a Red Plus: WD121KFBX at 2.8 W, with WD120EFBX at 2.9 W. At 16 TB and 20 TB the Red Pro models print 3.6 W to 3.8 W, against 6.3 W on the Exos X24 and 5.1 W on the older X18 at 16 TB. What the X24 offers for its watts is on its own sheet: 512 MB of cache and a 285 MB/s maximum sustained rate at the outer diameter, against 256 MB and 270 MB/s on the X18.

At 10 TB the Exos option on Seagate's sheets is the X16: ST10000NM001G gives 256 MB of cache, 245 MB/s (233 MiB/s), 5.0 W Idle A, 2,500,000 hours MTBF and a 5-year limited warranty. That puts it between the 4.6 W and 6.1 W Red models at the same size on idle.

Exos vs WD Red prices on Amazon.co.uk by capacity

Lowest price per TB at each matched size, new rows on Amazon.co.uk, pounds sterling inc VAT. Each row is one line at one size; a dash means no in-stock row at that size now. Red Plus stops at 12 TB, so the larger sizes are Exos against Red Pro.

The Exos table takes SAS and 2.5-inch rows as well as SATA, and leaves out titles carrying NM000C or NM002C. On the Red tables, read the model number on each row: at 12 TB it separates a 20 dBA drive from a 34 dBA one, and a 2.8 W drive from a 6.1 W one. Recording technology appears only where a document names the part number.

Seagate Exos or WD Red for a NAS: the short version

• Quiet room, low power: a 12 TB WD121KFBX (Red Pro) or WD120EFBX (Red Plus), at 20 dBA idle and under 3 W on WD's sheets.
• Heavier traffic: Red Pro is rated 550TB a year and the Exos X24 manual sets a ceiling under 550TB; Red Plus is rated 180TB.
• Warranty: Red Pro and Exos X24 both carry 5 years; Red Plus carries 3.
• Above 12 TB: Red Plus stops, so the choice is Red Pro or Exos.

Whether your NAS model accepts a given drive is for its maker's own compatibility list. Exos generations sit on Seagate Exos, and the two Red lines covered here have their own pages at WD Red Plus and WD Red Pro. Red Pro against WD's data centre line is on Ultrastar vs Red Pro.