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Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache 128MB 5400rpm NAS Compatible WD40EFZZ-AJP Eco Package
Western Digital

Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache 128MB 5400rpm NAS Compatible WD40EFZZ-AJP Eco Package

Bottom line: The Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache: CMR recording, not SMR - no write-slowdown on NAS rebuilds or large transfers; main trade-off: 5400rpm class trails 7200rpm drives on sustained sequential throughput.

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By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014, focused on GPU performance across gaming, rendering, and local-LLM inference. Synthesises community benchmarks, manufacturer specs, and public forum data into actionable buying guides.

Pros & Cons

Pros

  • ✓ CMR recording, not SMR - no write-slowdown on NAS rebuilds or large transfers
  • ✓ 4TB at 5400rpm class runs cooler and quieter than 7200rpm NAS drives
  • ✓ 128MB cache absorbs bursty multi-user NAS reads and writes
  • ✓ Standard 3.5-inch SATA form factor drops into most NAS bays and desktops

Cons

  • ✗ 5400rpm class trails 7200rpm drives on sustained sequential throughput
  • ✗ Eco Package ships with no retail box, mounting screws, or SATA cable
  • ✗ WD40EFZZ-AJP is a JP-market SKU, so labeling and support routing may differ
  • ✗ At 4TB, cost per terabyte is higher than larger Red Plus capacities

Manufacturer description

1

SpecPicks Verdict

SpecPicks scored Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache… using a rating × review-volume × price-fit model applied to published specs and reviews across the PC & gaming hardware category. Western Digital's PC & gaming hardware 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 PC & gaming hardware 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.

Full Specifications

BrandWestern Digital
Model NameRedPlus
Unit Count1 Count
Form Factor3.5-inch
Model NumberWD40EFZZ
Built-In MediaNo
Hard Disk Size4 TB
Hard-Drive Size4 TB
Mfr Part NumberWD40EFZZ
Number of Items1
Special FeatureDesigned for NAS
Installation TypeInternal Hard Drive
Data Transfer Rate150 megabits_per_second
Additional FeaturesDesigned for NAS
Hard Disk InterfaceSerial ATA
Hard Disk DescriptionMechanical Hard Disk
Hard Disk Form Factor3.5 inches
Hardware ConnectivitySATA 6.0 Gb/s
Connectivity TechnologySATA
Digital Storage Capacity4 TB

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Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache 128MB 5400rpm NAS Compatible WD40EFZZ-AJP Eco Package 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.

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Western Digital WD RedPlus Internal HDD 4TB CMR 3.5 Inch SATA Cache 128MB 5400rpm NAS Compatible WD40EFZZ-AJP Eco Package
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