Amazon US · exact models
Models to compare
New listing
Western Digital WD Red Plus
WD40EFPX · 4.0TBCompare the Red Plus 4TB model.
$231.23$57.81/TB
View new offer on Amazon ↗ Price checked Sep 12, 2026 11:44 UTC. Amazon's price and availability at purchase apply.New listing
Seagate IronWolf
ST4000VN006 · 4.0TBCapacity-matched IronWolf 4TB alternative.
$189.99$47.50/TB
View new offer on Amazon ↗ Price checked Sep 12, 2026 11:44 UTC. Amazon's price and availability at purchase apply.Start with the enclosure and capacity you need
Both families include CMR SATA drives intended for NAS use. For the models compared here, the manufacturers specify up to eight drive bays, a 180 TB/year workload rating and a three-year limited warranty for eligible new drives. Those shared specifications do not establish a reliability winner. Start with the compatibility list for your exact NAS, the capacity you need after redundancy, and the total price of the number of drives you will install.
At 4TB, compare WD40EFPX with ST4000VN006
These two models both specify 5,400 RPM and 256MB cache. If both are supported by your enclosure, compare current offer price, seller, return window and warranty eligibility. Do not accidentally substitute ST4000VN008: that IronWolf model has a different spindle speed and cache. A listing saying only IronWolf 4TB leaves an important part of the choice unresolved.
At 8TB, the spindle speed differs
WD80EFPX specifies 5,640 RPM, while ST8000VN004 specifies 7,200 RPM; both list 256MB cache. Spindle speed is one input to a storage decision, not a promise of application performance. Network speed, workload, enclosure cooling and array layout also matter. We have not tested their acoustics side by side, so this guide does not label either drive the quieter choice.
At 12TB, the suffix matters even within Red Plus
WD120EFBX and WD120EFGX are both 12TB Red Plus models, but their published cache and construction differ. The EFBX has 256MB cache and helium construction; the EFGX has 512MB cache and air construction. IronWolf ST12000VN0008 lists 256MB cache. Keep the full suffix in your comparison and avoid treating a capacity filter as an exact-model match.
A practical buying decision
Shortlist supported exact models first. Compare equivalent new offers, or evaluate renewed offers separately. For a two-drive NAS, compare the cost of the pair and leave room for an independent backup. If a seller changes the selected variant at checkout, check the model again. Follow the linked catalog entries for the source specifications and direct Amazon US listings; prices are kept separate from this guide’s hardware comparison.
Quick Decision Guide
| Capacity | WD Red Plus | Seagate IronWolf | Published difference |
|---|---|---|---|
| 4TB | WD40EFPX | ST4000VN006 | Both 5,400 RPM / 256MB |
| 8TB | WD80EFPX | ST8000VN004 | 5,640 vs 7,200 RPM |
| 12TB | WD120EFBX | ST12000VN0008 | Both 7,200 RPM / 256MB |
Frequently Asked Questions
Are these recommendations based on Disk Scout benchmark testing?
Does a manufacturer warranty apply to a renewed offer?
Sources
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Related Guides
WD Red Plus models
Compare the full model suffixes.
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IronWolf vs IronWolf Pro
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WD Red Plus vs Red Pro
Choose by workload and eligible warranty.
NAS noise and power
Plan a NAS for the room where it will run.