NAS Drive Compatibility

Western Digital Red 4TB

NAS HDD

Part number WD40EFAX · Red series · SATA 6Gb/s (SATA III). If your machine is listed below, this drive is officially supported — not a forum workaround.

RedNAS HARD DRIVE3.5" SATA HDDWESTERN DIGITAL

Part of the Western Digital Red series →

Check WD40EFAX price on Amazon  partner link

147
Compatible NAS models
0 Syn · 147 QNAP · 0 Asus · 0 TM
By vendor
4 TB
Listed capacity
Western Digital
Manufacturer
NAS (older line)
Product line (manufacturer rating)
5400
Spindle speed (RPM)
CMR/SMR
Recording
256 MB
Cache
180 TB
Rated workload / year

Specifications are the manufacturer's published ratings for this product series; verify the exact part number before purchase.

Strong pick as a cold copy

Recording for this series is mixed CMR/SMR — it varies by exact model number. Verify the exact part number before buying a cold copy: SMR drives throttle writes once their internal cache is full, which is exactly what a full-library backup pass does — a 16 TB cold-copy backup that takes days will slow to crawl on the last terabytes. For the off-site slot of a 3-2-1 plan, prefer the CMR variant of the same capacity; the 3-2-1 guide and the backup tools encyclopedia cover the rest of the chain.

Compatibility verdict

It appears on the official compatibility lists of 147 machines and series — 147 QNAP. This is a NAS-class drive: built for 24/7 operation with vibration compensation for multi-bay enclosures — the right tier for most 1-8 bay home or small-office NAS units. Its series rating is on file as SMR (shingled) — the one trait that slows large RAID rebuilds and full-library copies.

Compatible NAS models

QNAP HS-251 See its full HCL → QNAP HS-251+ See its full HCL → QNAP TAS-268 See its full HCL → QNAP TS-1277 See its full HCL → QNAP TS-131 See its full HCL → QNAP TS-131P See its full HCL → QNAP TS-216G See its full HCL → QNAP TS-230 See its full HCL → QNAP TS-231 See its full HCL → QNAP TS-231+ See its full HCL → QNAP TS-231P See its full HCL → QNAP TS-231P2 See its full HCL → QNAP TS-251 See its full HCL → QNAP TS-251+ See its full HCL → QNAP TS-251A See its full HCL → QNAP TS-251B See its full HCL → QNAP TS-251D See its full HCL → QNAP TS-253A See its full HCL → QNAP TS-253B See its full HCL → QNAP TS-253Be See its full HCL → QNAP TS-253D See its full HCL → QNAP TS-253E See its full HCL → QNAP TS-253 Pro See its full HCL → QNAP TS-328 See its full HCL → QNAP TS-332X See its full HCL → QNAP TS-431 See its full HCL → QNAP TS-431+ See its full HCL → QNAP TS-431P See its full HCL → QNAP TS-431P2 See its full HCL → QNAP TS-431U See its full HCL → QNAP TS-431X See its full HCL → QNAP TS-431X2 See its full HCL → QNAP TS-431XU See its full HCL → QNAP TS-431XU-RP See its full HCL → QNAP TS-431XeU See its full HCL → QNAP TS-432X See its full HCL → QNAP TS-432XU See its full HCL → QNAP TS-432XU-RP See its full HCL → QNAP TS-433eU See its full HCL → QNAP TS-451 See its full HCL → QNAP TS-451+ See its full HCL → QNAP TS-451A See its full HCL → QNAP TS-451D2 See its full HCL → QNAP TS-451S See its full HCL → QNAP TS-451U See its full HCL → QNAP TS-453A See its full HCL → QNAP TS-453B See its full HCL → QNAP TS-453BT3 See its full HCL → QNAP TS-453BU See its full HCL → QNAP TS-453Be See its full HCL → QNAP TS-453Bmini See its full HCL → QNAP TS-453D See its full HCL → QNAP TS-453E See its full HCL → QNAP TS-453S Pro See its full HCL → QNAP TS-453U See its full HCL → QNAP TS-453U-RP See its full HCL → QNAP TS-453 Pro See its full HCL → QNAP TS-453mini See its full HCL → QNAP TS-463U See its full HCL → QNAP TS-463U-RP See its full HCL → QNAP TS-463XU See its full HCL → QNAP TS-463XU-RP See its full HCL → QNAP TS-473 See its full HCL → QNAP TS-473A See its full HCL → QNAP TS-531P See its full HCL → QNAP TS-531X See its full HCL → QNAP TS-563 See its full HCL → QNAP TS-632X See its full HCL → QNAP TS-651 See its full HCL → QNAP TS-653A See its full HCL → QNAP TS-653B See its full HCL → QNAP TS-653D See its full HCL → QNAP TS-653 Pro See its full HCL → QNAP TS-673 See its full HCL → QNAP TS-673A See its full HCL → QNAP TS-677 See its full HCL → QNAP TS-831X See its full HCL → QNAP TS-831XU See its full HCL → QNAP TS-831XU-RP See its full HCL → QNAP TS-832X See its full HCL → QNAP TS-832XU See its full HCL → QNAP TS-832XU-RP See its full HCL → QNAP TS-851 See its full HCL → QNAP TS-853A See its full HCL → QNAP TS-853S Pro See its full HCL → QNAP TS-853U See its full HCL → QNAP TS-853U-RP See its full HCL → QNAP TS-853 Pro See its full HCL → QNAP TS-855X See its full HCL → QNAP TS-855eU See its full HCL → QNAP TS-855eU-RP See its full HCL → QNAP TS-863U See its full HCL → QNAP TS-863U-RP See its full HCL → QNAP TS-863XU See its full HCL → QNAP TS-863XU-RP See its full HCL → QNAP TS-873 See its full HCL → QNAP TS-873A See its full HCL → QNAP TS-873U-RP See its full HCL → QNAP TS-877 See its full HCL → QNAP TS-932X See its full HCL → QNAP TS-963X See its full HCL → QNAP TS-977XU See its full HCL → QNAP TS-977XU-RP See its full HCL → QNAP TS-983XU See its full HCL → QNAP TS-983XU-RP See its full HCL → QNAP TS-AI642 See its full HCL → QNAP TS-h765eU See its full HCL → QNAP TVS-1282 See its full HCL → QNAP TVS-1282T See its full HCL → QNAP TVS-1282T3 See its full HCL → QNAP TVS-1582TU See its full HCL → QNAP TVS-463 See its full HCL → QNAP TVS-471 See its full HCL → QNAP TVS-472XT See its full HCL → QNAP TVS-473 See its full HCL → QNAP TVS-473e See its full HCL → QNAP TVS-663 See its full HCL → QNAP TVS-671 See its full HCL → QNAP TVS-672X See its full HCL → QNAP TVS-672XT See its full HCL → QNAP TVS-673 See its full HCL → QNAP TVS-673e See its full HCL → QNAP TVS-682 See its full HCL → QNAP TVS-682T See its full HCL → QNAP TVS-863 See its full HCL → QNAP TVS-863+ See its full HCL → QNAP TVS-871 See its full HCL → QNAP TVS-871T See its full HCL → QNAP TVS-872X See its full HCL → QNAP TVS-872XT See its full HCL → QNAP TVS-873 See its full HCL → QNAP TVS-873e See its full HCL → QNAP TVS-882 See its full HCL → QNAP TVS-882BR See its full HCL → QNAP TVS-882BRT3 See its full HCL → QNAP TVS-882T See its full HCL → QNAP TVS-951X See its full HCL → QNAP TVS-972XU See its full HCL → QNAP TVS-972XU-RP See its full HCL → QNAP TVS-h1288X See its full HCL → QNAP TVS-h1688X See its full HCL → QNAP TVS-h474 See its full HCL → QNAP TVS-h674 See its full HCL → QNAP TVS-h674T See its full HCL → QNAP TVS-h874 See its full HCL → QNAP TVS-h874T See its full HCL → QNAP TVS-h874X See its full HCL →

Same-capacity alternatives

Other drives listed at 4 TB capacity, ranked by how many machines list them:

Toshiba MG04ACA400E 451 machines · MG04ACA**** Western Digital WD4003FFBX 390 machines · Red Pro Seagate ST4000NE0015 379 machines · Enterprise NAS HDD Toshiba MG04ACA400N 353 machines · MG04ACA**** Western Digital WD40PURZ 352 machines · Purple Seagate ST4000NM002A 346 machines · Exos 7E8 Seagate ST4000NE0025 344 machines · IronWolf Pro Western Digital HUS726T4TALA6L4 333 machines · Ultrastar 7K6

Quick answers

Is the WD40EFAX officially compatible with my NAS?

It appears on the official compatibility lists of 147 machines and series — 147 QNAP. Every machine page linked below shows the vendor's own list entry, refreshed daily.

Is the WD40EFAX CMR or SMR?

As a Western Digital Red drive, it is rated CMR/SMR varies by model. CMR (conventional magnetic recording) is what a RAID array wants: SMR drives slow rebuilds dramatically. This series mixes both, so verify the exact part number before buying — the <a href="/faq/cmr-vs-smr-nas-drives/">CMR vs SMR guide</a> has a part-number lookup.

Is the WD40EFAX a good NAS drive?

This is a NAS-class drive: built for 24/7 operation with vibration compensation for multi-bay enclosures — the right tier for most 1-8 bay home or small-office NAS units. Its series rating is on file as SMR (shingled) — the one trait that slows large RAID rebuilds and full-library copies.

Can I use the WD40EFAX for a 3-2-1 cold backup copy?

Recording for this series is mixed CMR/SMR — it varies by exact model number. Verify the exact part number before buying a cold copy: SMR drives throttle writes once their internal cache is full, which is exactly what a full-library backup pass does — a 16 TB cold-copy backup that takes days will slow to crawl on the last terabytes. For the off-site slot of a 3-2-1 plan, prefer the CMR variant of the same capacity; the 3-2-1 guide and the backup tools encyclopedia cover the rest of the chain.

What are alternatives to the WD40EFAX?

At the same capacity, the most widely listed alternatives are Toshiba MG04ACA400E (451 machines), Western Digital WD4003FFBX (390 machines), Seagate ST4000NE0015 (379 machines). The full ranked list is below.