WD Red Plus 4TB NAS Internal Hard Drive (WD40EFZZ) – SATA 6Gb/s, 5400 RPM, 128MB Cache, CMR

The WD Red Plus 4TB (WD40EFZZ) is a 3.5-inch CMR NAS hard drive for home NAS users, homelabs and small offices running 1–8 bay systems. NASware 3.0 firmware, a 128MB cache and 5400 RPM operation deliver predictable RAID performance and reliable 24/7 storage for growing files.

Always-on NAS capacity built around CMR and RAID-tuned firmware.

How CMR and NASware 3.0 Protect Your RAID Array

Most NAS problems start with the wrong drive. Desktop drives are designed for a few hours of use per day, while a NAS runs around the clock with several drives sharing heat and vibration. SMR drives add a second risk: they overlap tracks, so sustained writes – like a RAID rebuild – can slow dramatically and stretch the time your array is unprotected.

The WD Red Plus 4TB avoids both problems. It uses CMR, so each track is written independently and rebuild speeds stay consistent, and NASware 3.0 limits error-recovery time so a hard-to-read sector doesn’t get the drive ejected from the array. At 4TB, it covers mainstream NAS capacity needs – shared files, databases or rolling backups – without paying for capacity you will not use.

CMR Recording – Predictable Performance Under Load

Write performance stays steady whether you are copying a single large file or rebuilding after a drive failure. With a 128MB cache and SATA 6Gb/s, the drive handles backups, media streaming and shared folders for several users at once.

Built for Always-On Multi-Bay Enclosures

The drive is rated for a 180TB/year workload and 1 million hours MTBF in 24/7 operation, and is designed for the vibration of multi-bay chassis with up to 8 drives. Its 5400 RPM-class spindle keeps heat, noise and power draw low in home and office NAS units.

Setup Instructions

How to Install the WD Red Plus 4TB in Your NAS

1. Check your NAS model’s compatibility list and power the unit down unless it supports hot-swap.
2. Mount the drive in an empty tray or bay using the enclosure’s screws or tool-less clips.
3. Power on – Synology DSM, QNAP QTS, TrueNAS and Unraid will detect the new drive automatically.
4. Create a new storage pool or add the drive to an existing RAID volume, then enable scheduled S.M.A.R.T. tests.