 "Western Digital Red 6 TB Internal HDD" " Western HDD - WD60EFRX Desktop Hard Drives CDW.com
"WD's exclusive NASware technology, built into every WD Red hard drive, improves NAS storage performance by reducing common hard drive concerns in NAS systems including concerns for things like compatibility, integration, upgradeability, reliability and cost of ownership that are experienced with a hard drive designed for desktop computers." 
 "WD 1TB 3.5" SATA Surveillance Storage Purple Hard Drive for CCTV DVR NVR & HOME PC System -WD10PURZ"@en
 Specification 1TB Model Number WD10PURZ Formatted capacity 1TB Form factor 3.5 inch Advance format (AF) Yes Interface transfer rate (max)   Buffer to host 6 Gb/s Host to/from drive (sustained) 110 MB/s Cache (MB) 64 Performance class / Rotational speed (RPM) 5400 RPM Class Weight (kg) 0.45