According to one embodiment, a storage device includes a first memory, an interface that includes first physical layers and connects a host and the first memory, a second memory that temporarily stores the data transferred between the host and the first memory, a controller that controls operation of the interface. When the data is transferred from the first memory to the host, the controller reads the data corresponding to the data transfer request into the second memory, the controller selects the physical layer to transfer the data from the second memory to the host based on a first period until the data is ready for transmission after data transfer is requested.