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4TB Purple WD42PURZ, 5400 RPM, SATA 6Gb/s, 256MB cache, 3.5" HDD

  • SKU: 14674623
  • Manufacturer: WESTERN DIGITAL
  • Availability: USUALLY SHIPS WITHIN 3-5 DAYS
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4TB Purple WD42PURZ, 5400 RPM, SATA 6Gb/s, 256MB cache, 3.5" HDD

Uncompromising Storage with a WD Purple Surveillance Hard Drive

WD Purple drives are engineered specifically for surveillance to help withstand the elevated heat fluctuations and equipment vibrations within NVR environments. An average desktop drive is built to run for only short intervals, not the harsh 24/7 always-on environment of a high-definition surveillance system. With WD Purple, you get reliable, surveillance-class storage that’s tested for compatibility in a wide range of security systems, and some of our latest models (WD22PURZ, WD42PURZ, and WD63PURZ) have improved power efficiency. Exclusive AllFrame™ technology helps reduce frame loss and improve overall video playback.

Model Number³ WD42PURZ
Formatted capacity? 4TB
Form factor 3.5-inch
Advanced Format (AF) Yes
Recording Technology CMR
RoHS compliant? Yes
Product Features
Cameras supported¹³ Up to 64 HD14
Drive Bays Supported 16
Al Streams --
Firmware Feature Name AllFrame
Tarnish resistant components Yes
Interface transfer rate (max)? Buffer to host
Host to/from drive (sustained)
6 Gb/s
175 MB/s
Cache (MB)? 256
Reliability/Data Integrity
Load/unload cycles? 300 000
Annualized workload rating? 180TB/yr
Non-recoverable read errors per bits read <1 in 10^14
MTBF 1 000 000
Limited warranty (years)? 3
Power Management9
Average power requirements (W) Read/Write
Standby and Sleep
Environmental Specifications10
Temperature (°C, on the base casting)
0 to 65
-40 to 70
Shock (Gs)
Operating (2 ms, read/write) Operating (2 ms, read)
Non-operating (2 ms)
Acoustics (dBA)12 Idle
Seek (average)
Physical Dimensions
Height (in./mm, max) 1.028/26.1
Length (in./mm, max) 5.787/147
Width (in./mm, ± .01 in.) 4/101.6
Weight (lb/kg, ± 10%) 1.58/0.72

1 MTBF specifications are based upon internal testing using a 40°C base casting temperature. MTBF is
based on a sample population and is estimated by statistical measurements and acceleration algorithms.
MTBF does not predict an individual drive’s reliability and does not constitute a warranty.
2 For capacities 4TB and higher.
3 Not all products may be available in all regions of the world.
4 As used for storage capacity, one gigabyte (GB) = one billion bytes and one terabyte (TB) = one trillion
bytes. Total accessible capacity varies depending on operating environment. As used for buffer or cache,
one megabyte (MB) = 1,048,576 bytes. As used for transfer rate or interface, megabyte per second (MB/s)
= one million bytes per second, and gigabit per second (Gb/s) = one billion bits per second. Effective
maximum SATA 6 Gb/s transfer rate calculated according to the Serial ATA specification published by the
SATA-IO organization as of the date of this specification sheet. Visit for details.
5 WD hard drive products manufactured and sold worldwide after June 8, 2011, meet or exceed
Restriction of Hazardous Substances (RoHS) compliance requirements as mandated by the RoHS Directive
6 Controlled unload at ambient condition.
7 Workload Rate is defined as the amount of user data transferred to or from the hard drive. Workload
Rate is annualized (TB transferred x (8760 / recorded power-on hours)). Workload Rate will vary
depending on your hardware and software components and configurations.
8 See for regional specific warranty details.
9 Power measurements at room-ambient temperature.
10 No non-recoverable errors during operating tests or after non-operating tests.
11 On the base casting.
12 Sound power level.
13 1TB through 3TB support up to eight bays; 4TB and above support up to 16 bays.
14 Single stream at 3.2Mbps (1080p, H.265, 25 fps). Results may vary depending on camera resolution, file format, frames per second, software, system settings, video quality, and other factors