I bought my used 9020 Dell Optiplex to run 4 x 2MP cameras' and continuous recording. Worked great! Now, I'm upto 11 cameras with 3 x 8MP. Had to change continuous to motion only because only have a 2TB Western Digital Purple harddrive. The manufacturer specs on this PC states can only go upto 2TB hard drive. I'm not sure if that means 2TB per SATA channel or 2TB total for the system. Anyone else with a Dell Optiplex that has a larger HD than 2TB?