Exos vs IronWolf Pro for NAS: Model Suffixes, Ratings and Seagate's Two Noise Documents

Exos vs IronWolf Pro for NAS: workload, MTBF and the model suffix

On workload, Seagate's two manuals say the same thing. The Exos X24 SATA manual gives a maximum rated workload of under 550TB a year, counted as terabytes per 8,760 power-on hours, and the IronWolf Pro SATA manual, which covers the 24, 20, 16 and 12 TB NT models, prints the same maximum rate of under 550TB a year. The split comes from the IronWolf Pro data sheets, which add a second, lower-rated model at several sizes.

Read with the suffix in mind, an NT IronWolf Pro and an Exos X24 sit on the same ratings: manual against manual, both under 550TB a year, and the same 2.5 million hours MTBF. An NE model sits well below both. The newer IronWolf Pro sheet, DS2129.4-2311US, lists only NT models, NT001 and NT002 at 24 TB, and no NE models; every model quoted from it here, 16 TB to 24 TB, is CMR with a 5-year limited warranty, the term the X24 sheet also gives. The NE models appear on the 2022 sheet, DS1914.21-2206US, which is where a 300 TB/year listing would come from. A title that says IronWolf Pro with no part number cannot tell you which you are buying.

Exos X16 vs IronWolf Pro and Exos X24 at 12TB and 16TB

Each row names its part number and, on the IronWolf Pro side, the sheet revision the figures come from. Sustained rate is the maximum at the outer diameter and idle is the average each sheet prints.

Exos X16 vs IronWolf Pro at 16 TB is close on paper. ST16000NM001G and ST16000NT001 share 256 MB of cache and 5.0 W idle; the X16 sheet gives 261 MB/s against the IronWolf Pro's 270 MB/s, and both state 2,500,000 hours MTBF and a 5-year limited warranty. We have not found a document that states an annual workload for the X16. The X24 at 16 TB is the different trade: twice the cache and 285 MB/s, at 6.3 W idle.

Exos X20 vs IronWolf Pro and Exos X24 vs IronWolf Pro at 18TB to 24TB

Above 16 TB the two IronWolf Pro sheets print different idle figures for the same NT001 models, so both revisions are shown rather than blended.

At 24 TB the two lines print identical rows: ST24000NT002 and ST24000NM002H both give 512 MB, 285 MB/s and 6.3 W idle. At 22 TB the newer IronWolf Pro sheet adds ST22000NT001 with 512 MB, 285 MB/s and 6.0 W. At 20 TB the Exos X20 and IronWolf Pro are nearly level on cache and transfer, with idle at 5.4 W on the X20 against 5.5 W or 5.7 W on ST20000NT001 depending on the sheet revision. One more detail from the 2022 sheet: ST18000NE000 sustains 260 MB/s where its NT001 sibling sustains 285 MB/s.

Exos vs IronWolf Pro noise: two Seagate documents, two answers

Seagate's own manuals give Exos and IronWolf Pro the same sound power. The IronWolf Pro SATA product manual, July 2025, covers ST24000NT002, ST20000NT001, ST16000NT001 and ST12000NT001 and defines its acoustics as overall A-weighted acoustic sound power levels, the wording the Exos X24 SATA manual uses. For all those models it prints 2.8 bels typical idle and 3.2 bels typical performance seek, with 3.0 and 3.4 bels maximum: the same four numbers the X24, X20 and X18 SATA manuals print for every Exos model they cover.

The IronWolf Pro data sheet prints something else for the same line: 20 dBA idle and 26 dBA seek at 20 TB and 18 TB. We have not found a document that states what quantity that dBA figure measures, or one that converts it to bels. So the honest reading is narrow. On the documents that define their method, Seagate gives Exos and IronWolf Pro identical sound power. The data sheet's dBA figure has nothing on the Exos side to sit beside.

We do not call either drive quieter. A claim that Exos is the louder of the two would need a document that tests both the same way, and the Seagate documents that state a method give both lines the same figures.

Exos vs IronWolf Pro prices on Amazon.co.uk at 12TB to 20TB

Prices are pounds sterling inc VAT from Amazon.co.uk, new condition. A dash means one side has no in-stock row at that size right now. Because NT and NE models share the IronWolf Pro table, read the part number on any row before you rely on the ratings above.

The Exos table holds every generation and interface, including SAS and 2.5-inch rows, and leaves out titles carrying NM000C or NM002C. At 16 TB the Exos rows can be X16 or X18 rather than X24, so match the part number to the tables above before reading figures across. Recording technology prints only where a document names the part number; Seagate's sheets state CMR for the X24 and for the IronWolf Pro models quoted here.

Exos vs IronWolf Pro for NAS: reading the choice off the sheets

• Workload: an NT IronWolf Pro and an Exos X24 both sit under 550TB a year on Seagate's manuals; an NE model is rated 300 TB on the 2022 sheet.
• Warranty and MTBF: NT001 and X24 both state 5 years and 2.5 million hours; an NE model states 1.2 million hours.
• At 24 TB, ST24000NT002 and ST24000NM002H print the same cache, transfer and idle figures.
• Noise: Seagate's manuals give the two lines the same sound power, so noise is not a reason to pick one.

Exos generations have their own pages at Exos X24 and Exos X16, with the whole range on Seagate Exos. The cheaper NAS line set against Exos is on Exos vs IronWolf.