Western Digital
Western Digital 4TB WD Red Plus NAS Internal Hard Drive HDD (WD40EFZZ)
Bottom line: The Western Digital 4TB WD Red Plus NAS Internal Hard Drive HDD ($189.99 on Amazon as of 2026-10-21 16:17 UTC, orderable but not in stock): CMR recording, not SMR, so RAID rebuilds and pool expansions stay predictable; main trade-off: 5400 RPM spindle trails 7200 RPM NAS drives on peak sequential throughput.
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*Price sourced from Amazon.com. Last updated 2026-10-21. Price and availability subject to change.
Pros & Cons
Pros
- ✓ CMR recording, not SMR, so RAID rebuilds and pool expansions stay predictable
- ✓ 128 MB cache plus SATA 6 Gb/s keeps multi-user NAS reads flowing
- ✓ NASware firmware tunes it for RAID-optimized enclosures up to 8 bays
- ✓ Designed for continuous operation, not desktop start-stop duty cycles
Cons
- ✗ 5400 RPM spindle trails 7200 RPM NAS drives on peak sequential throughput
- ✗ 4TB sits mid-pack in a 2TB-12TB family; large media libraries outgrow it
- ✗ Tuned for enclosures up to 8 bays; larger arrays want a higher-tier drive
- ✗ 3.5-inch SATA only, so it will not fit 2.5-inch or M.2 NAS bays
Manufacturer description
The Western Digital 4TB WD Red Plus (WD40EFZZ) is a 3.5-inch NAS hard drive built for arrays that never power down. It uses CMR - conventional magnetic recording - rather than SMR, which matters the moment you rebuild a degraded RAID volume or expand an existing pool, because CMR writes land in place instead of forcing a shingled rewrite pass. A 128 MB cache and a SATA 6 Gb/s interface keep multi-user reads moving, while the 5400 RPM-class spindle trades peak sequential throughput for lower heat and quieter operation in a stacked bay. Western Digital's NASware firmware tunes the drive for…
SpecPicks Verdict
SpecPicks scored Western Digital 4TB WD Red Plus NAS Internal Hard Drive HDD using a rating × review-volume × price-fit model applied to published specs and reviews across the drives & media category. Western Digital's drives & media lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for drives & media of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
Is the WD40EFZZ a CMR or SMR drive?
It is CMR (conventional magnetic recording). That is the spec that matters for RAID, since CMR avoids the shingled rewrite penalty SMR drives hit during rebuilds and heavy sustained writes.
How many NAS bays does this WD Red Plus support?
Western Digital rates the Red Plus line for RAID-optimized NAS systems with up to 8 bays. Beyond 8 bays you should step up to a drive class rated for larger arrays.
Is 5400 RPM fast enough for a media server or Plex box?
For streaming and file serving the bottleneck is usually the network and the 128 MB cache plus SATA 6 Gb/s link, not the spindle. If you need maximum single-stream sequential speed, a 7200 RPM drive will be quicker.
Can I use this drive in a regular desktop PC instead of a NAS?
Yes - it is a standard 3.5-inch drive with a SATA 6 Gb/s connector, so it drops into any desktop with a free 3.5-inch bay and SATA port. It is designed for continuous operation, so leaving it powered on is expected.
Key Features
- Available in capacities ranging from 2TB to 12TB
- For RAID-optimized NAS systems with up to 8 bays
- Designed for Continuous Operation
- Backed by World-Class Support and Warranty
- Tuned for NAS with NASware
Full Specifications
| Brand | Western Digital |
|---|---|
| Color | Red |
| Model Name | WD Red |
| Read Speed | 180 megabytes_per_second |
| Form Factor | 3.5-inch |
| Media Speed | 180 |
| Model Number | WD40EFZZ-SPCPAN0 |
| Built-In Media | hard drive |
| Hard-Drive Size | 4 TB |
| Mfr Part Number | WD40EFZZ |
| Number of Items | 1 |
| Special Feature | 3-year limited warranty, NASware, Rotation Vibration (RV) sensors |
| Hardware Platform | WD |
| Installation Type | Internal Hard Drive |
| Compatible Devices | Desktop |
| Data Transfer Rate | 180 megabits_per_second |
| Enclosure Material | Information Not Available |
| Additional Features | 3-year limited warranty, NASware, Rotation Vibration (RV) sensors |
| Hard Disk Interface | Serial ATA-600 |
| Warranty Description | 3 year limited warranty |
| Full listing title | Western Digital 4TB WD Red Plus NAS Internal Hard Drive HDD - 5400 RPM, SATA 6 Gb/s, CMR, 128 MB Cache, 3.5" - WD40EFZZ |
Ready to buy?
Western Digital 4TB WD Red Plus NAS Internal Hard Drive HDD - 5400 RPM, SATA 6 Gb/s, CMR, 128 MB Cache, 3.5" - WD40EFZZ is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-10-21. Price and availability subject to change.
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