A system includes a plurality of storage devices and a controller. The plurality of storage devices are bus-connected to one clock signal line and one data signal line connected to the controller. Each of the plurality of storage devices stores identification information in advance to distinguish the storage devices from each other. The controller transmits data using an identification information transmission period in which one storage device is selected from the plurality of storage devices by transmitting the identification information of the one storage device to the plurality of storage devices via the data signal line and a data transmission period in which the data is transmitted to the one selected storage device. A frequency of a clock signal during the identification information transmission period is set to be lower than a frequency of the clock signal during the data transmission period.