A display device includes a first connector which receives a first image signal and first driving power, a second connector which receives a second image signal and second driving power, a first control unit which processes the first image signal and the first driving power, a second control unit which processes the second image signal and the second driving power, a power management unit which receives the first and second driving powers from the first control unit and the second control unit, measures the first and second driving powers, and provides information about the first driving power and information about the second driving power to the first and second control units, and a display unit which receives one of the first and second image signals from one of the first and second control units and displays one of the first and second image signals.