Apparatus and method for power saving of computer system

According to an embodiment of the present invention there is provided a first computer system comprising a first computer and a first display device. And the first computer includes a processor. It said first display device is connected to the first computer, and displays the graphic signal. Wherein the processor is a second computer and a second receiving at least one of information of system status information and power status information from a computer system including a display device, and the first power saving control on the basis of the received status information, It generates a command. And wherein the processor transmits the first power saving control command to the second computer system. The first power saving control command is a command for controlling at least one of the power saving of the second computer and the second display device.