A motherboard includes a switching circuit, a serial advanced technology attachment (SATA) connector connected to a hard disk drive (HDD), a first serial attached small computer system interface (SCSI) (SAS) connector, and a connector connected to an SAS card. A second SAS connector is arranged on the SAS card and connected to the first SAS connector. The switching circuit is connected to the SATA connector and the first SAS connector. The switching circuit is disconnected from the first SAS connector if the HDD is an SATA HDD. The motherboard communicates with the HDD through the switching circuit and the SATA connector. The switching circuit is connected to the first SAS connector if the HDD is an SAS HDD. The motherboard communicates with the HDD through the SAS card, the first SAS connector, the switching circuit, and the SATA connector.