A memory module is provided including a plurality of semiconductor memory devices mounted on a circuit board. A control device is mounted on the circuit board and configured to receive a command signal, an address signal, and a clock signal and to provide the command signal, the address signal, and the clock signal to the plurality of semiconductor memory devices. A first group of the semiconductor memory devices is disposed between the control device and a first edge portion of the circuit board, and a second group of the semiconductor memory devices is disposed between the control device and a second edge portion of the circuit board. The control device is configured to transmit the address signal to the first group of the semiconductor memory devices and the second group of the semiconductor memory devices through a first transmission line and a second transmission line, respectively. The first transmission line and the second transmission line are physically symmetric with respect to an axis intersecting the control device.