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.

There are three main tasks HDDs do besides storage: read data, write data, and transfer data. Generally, surveillance HDDs are turned on 24 hours/7 days a week. They write data and store footage from security video most of the time. They transfer them only a small portion of the time. Regular HDDs are designed for being used mostly to read data and are not typically tested for use in a 24x7 surveillance environment with the continuous demand of writing videos. Video surveillance HDDs are designed to endure heavy writing, from several closed-circuit television (CCTV) cameras simultaneously, consume low power, and endure environments with a wide range of temperatures.