Western Digital Purple 4TB Surveillance 3.5in Hard Drive, SATA III w/ 256MB Cache

MX00121858 Purple 4TB Surveillance 3.5in Hard Drive, SATA III w/ 256MB Cache
MX00121858 Purple 4TB Surveillance 3.5in Hard Drive, SATA III w/ 256MB Cache MX00121858 Purple 4TB Surveillance 3.5in Hard Drive, SATA III w/ 256MB Cache

Product Info

WD Purple™ drives are built for 24/7, always-on, high-definition security systems. WD Purple™ surveillance hard drives feature Western Digital’s exclusive AllFrame™ technology, so you can confidently create a security system tailored to the needs of your business. Using AllFrame™ technology, WD Purple™ drives improve video capturing and help to reduce errors, pixelation, and video interruptions that can occur in a video recorder system. WD Purple drives have an enhanced workload rating that supports systems designed for 24x7 video recording with up to 64 cameras.


Uncompromising Storage

Built for 24/7, always-on, high-definition security systems. With a supported workload rate of 180 TB/yr and support for up to 64 cameras, WD Purple drives are optimized for surveillance systems.

  • The Right Drive for the Job:
    WD Purple drives have been engineered specifically for the extreme demands of high temperature, 24/7 surveillance systems
  • Performance You Can Trust:
    From a worldwide leader in the storage industry, WD Purple is engineered for quality video playback when you need it most.
  • Expand Your View to 64
    WD Purple drives are optimized to support up to 64 cameras, giving you flexibility to upgrade or expand your security system.

Seamless Integration

With a wide range of industry-leading enclosures and chipsets supported, you're sure to find the configuration and compatibility that's right for your NVR.


Less Is More

Low power consumption is a must in a high-temperature, always-on surveillance environment. IntelliSeek Technology helps reduce damaging ambient noise and vibrations.

  • What is the difference between a desktop drive and a WD Purple drive?
    The WD Purple drive is designed specifically for 24/7 DVR and NVR surveillance solutions and is optimized with AllFrame™ technology for system playback and performance. WD Purple drives support 3x the workload rating of desktop drives, making them more capable of handling the higher demands of video surveillance systems
  • What capacity do you recommend for my surveillance?
    Higher capacity WD Purple drives allow you to store more footage, more high definition video, and more high quality frames per second. WD recommends 4TB or greater for your DVR or NVR surveillance solution
  • Easy Backup and Upgrade
    Acronis True Image WD Edition software, available as a free download, can clone drives and backup your operating system, applications, settings and all of your data

Designed for Surveillance

The WD Purple drive is designed for both DVR and NVR security systems, and is compatible with many of the the leading surveillance and security manufacturers. We can help you find the perfect storage for your system.

Check Compatibility

Trust Your View
All WD Purple drives are equipped with AllFrame™ technology, which improves ATA streaming to reduce frame loss, improve overall video playback, and more.

3-Year Limited Warranty

Every WD Purple drive comes with a 3-year limited warranty, so you can be confident of your surveillance storage.

Additional Information:

Visit the Manufacturer Web Page for Full Details

Download the Manufacturer Specification Sheet




WD Purple HDDs are built for personal, home office and small business surveillance using up to 64 HD cameras at once.


Make and Model Western Digital Purple Surveillance HDD
Part Number WD42PURZ
Formatted Capacity 4TB1
Interface SATA III, 6 Gb/s maximum
Form Factor 3.5"
Transfer Rate Sustained: 175 MB/second
Rotational Speed 5400rpm
Cache 256MB
MTBF 1,000,000 hours
Load / Unload 300,000 Cycles
Annualized workload rating 180 TB/yr
Read Errors <1 in 1014
Acoustics Idle: 23 dBA
Seek Mode: 27 dBA
Shock Operating (2 ms, read/write): 30 Gs
Operating (2 ms, read): 65 Gs
Non-operating (2ms): 250 Gs
Temperature Operating: 0 ~ 65° C
Non-Operating: -40 ~ 70° C
Power Input N/A
Power Usage Typical Read / Write: 4.6W
Idle: 3.7W
Standby & Sleep Modes: 0.3W
Dimensions & Weight  
Dimensions (WxLxH) 101.6 x 147.0 x 26.1 mm (4" x 5.79" x 1.03")
Weight 570g (1.26 lb.)
  1. As used for storage capacity, one megabyte (MB) = one million bytes, one gigabyte (GB) = one billion bytes, and one terabyte (TB) = one trillion bytes. Total accessible capacity varies depending on operating environment.