Western Digital Purple 3TB 5400 RPM Surveillance Desktop Internal Hard Disk Drive ( WD30PURZ )

Engineered specifically for surveillance security systems
Supports up to 180 TB/yr. workload rate
Prioritized write-operations for maximized surveillance performance
Support for more than eight bays
Tarnish-resistant components
Tuned for write-intensive, low bit-rate, high stream-count applications typical to most surveillance applications
TLER and ATA streaming support