A data processing control system has a controller wherein the controller (1) sends every received instruction to the plurality of data processing devices until the number of instructions being executed or waiting to be executed by the plurality of data processing devices reaches a predetermined number, (2) does not send any received instructions to the plurality of data processing devices but holds the received instructions in a queue once the number of instructions being executed or waiting to be executed by the plurality of data processing devices has reached the predetermined number, and (3) when the number of instructions being executed or waiting to be executed by the plurality of data processing devices has become zero by completing the execution thereof, starts sending the queued instructions in sequence to the plurality of data processing devices, and continues to send the queued instructions or every newly received instruction to the plurality of data processing devices until the number of instructions being executed or waiting to be executed by the plurality of data processing devices reaches the predetermined number.