A load of a data channel at the time of data writing is reduced. A memory controller includes a specific data pattern retaining unit, a comparator, and an issuance unit. The specific data pattern retaining unit retains a specific data pattern. The comparator compares write data regarding a write command from a host computer with the specific data pattern. The issuance unit issues a specific write request that requests writing of the specific data pattern without supplying the write data to a memory in a case where the write data matches the specific data pattern.