In order to improve throughput by suppressing contention of hardware resources in a computer to which a data transfer unit is coupled, a control unit for transferring data between a first interface coupled to the computer and a second interface coupled to a memory transaction issuing unit for issuing, when one of the first interface and the second interface receives an access request to a memory of the computer, a memory transaction for the main memory to the first interface, the first interface includes a plurality of interfaces coupled in parallel to the computer, and the control unit further includes a memory transaction distribution unit for extracting an address of the main memory, which is contained in the memory transaction issued by the memory transaction issuing unit, and selecting an interface having address designation information set therein, which corresponds to the extracted address to transmit the memory transaction.