A command control system is provided which is configured to optimally set an output timing of a RAS command and an output timing of a CAS command for access requests different from each other. The command control system is configured to, when an output timing of a second RAS command is set in a first cycle time period which is a cycle starting from the reference time point, determine whether or not the second RAS command is output to a storage device in the first cycle time period in accordance with whether or not an output timing of a first CAS command is set in a second cycle time period constituted by a prescribed number of the cycles subsequent to the reference time point.