WD Blue 4TB WD40EZRZ internal hard drive: specs and who it suits

The WD Blue 4TB (model WD40EZRZ) is an internal 3.5-inch hard drive for desktop computers. It stores data on spinning magnetic platters, which is why it offers a lot of space in a conventional, well-understood format. Western Digital positions it as a primary drive for office and web use.

What a 5400 RPM hard drive is

Inside the case, platters spin at 5,400 revolutions per minute while a read/write head moves across them. Compared with 7,200 RPM drives, a 5,400 RPM drive typically runs a little cooler and quieter, and it often draws less power. Sequential transfers are usually fine for documents, photos and media, but it will feel slower than any SSD when you start an operating system or open many small files.

SATA 6 Gb/s and the 64 MB cache

The drive uses the SATA 6 Gb/s interface, the standard connector on most desktop motherboards. SATA is backwards compatible, so it generally works on older ports at lower link speeds. The 64 MB cache is a small memory buffer on the drive that smooths out bursts of reads and writes. A hard drive's real-world speed is limited mostly by the spinning platters, not the interface.

4TB of space for everyday files

Four terabytes is plenty for large photo libraries, music, documents, backups and a good number of video files. Western Digital says the WD Blue range goes up to 6 TB, so this is a mid-range size within the family. Operating systems report a little less than the labelled capacity, because manufacturers count in decimal units.

Size and fit

The listing gives the dimensions as 5.9 x 4.0 x 1.0 inches (about 15 x 10 x 2.5 cm), and the weight as 1.5 lb (about 0.7 kg). That is the standard 3.5-inch desktop size. It fits a desktop drive bay, not a typical laptop, which uses 2.5-inch drives.

Cloning software

Western Digital lists Acronis True Image WD Edition cloning software with the drive. Cloning copies the contents of an old drive onto a new one, which can make migration simpler. Check Western Digital's site for how to get the software and which drives it supports.

Who it suits

It suits desktop owners who want a large amount of space for documents, media or backups, or a second drive alongside an SSD that holds the operating system. Western Digital describes it for office and web applications and everyday computing.

What to check before you buy

• Bay and connectors: confirm your case has a free 3.5-inch bay and your system has a free SATA data port and a SATA power connector.
• Use case: a hard drive suits bulk storage; for booting or loading programs quickly, an SSD is typically the faster choice.
• Noise and heat: spinning drives make some sound, so consider case placement and airflow.
• Backups: any single drive can fail, so keep important data copied somewhere else.
• Warranty and software: check the manufacturer's terms and the cloning software's requirements.

The short version

• Internal 3.5-inch hard drive, 4TB, model WD40EZRZ from Western Digital.
• 5400 RPM, SATA 6 Gb/s, 64 MB cache.
• Aimed at desktop PCs and office applications.
• Includes Acronis True Image WD Edition cloning software, according to the listing.
• Standard desktop size, not for most laptops.

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