Western Digital WD20PURX 4TB Purple Surveillance Hard Drive

The Western Digital WD Purple WD20PURX is a 3.5-inch internal hard drive purpose-built for surveillance systems. Unlike desktop drives that prioritize random read/write performance, the WD Purple's firmware is tuned for the write-intensive, low-bitrate, high-stream-count workloads that characterize security DVRs, NVRs, and IPTV set-top boxes. Its AllFrame technology manages cache allocation to prioritize write operations and reduce the video frame loss and error pixelation that can plague standard drives under continuous multi-camera recording loads.

With a 4TB capacity, 5400 RPM IntelliPower spindle speed, and 64MB cache, the WD Purple balances storage space with the thermal and power efficiency needed for always-on operation inside enclosed surveillance appliances. The SATA III 6Gb/s interface delivers a sustained data transfer rate of up to 110MB/s, sufficient for handling up to 32 camera streams simultaneously. The drive is backed by a 3-year limited warranty, reflecting Western Digital's confidence in its durability under continuous workloads. For surveillance system builders, the WD Purple remains a proven, category-specific storage solution.