Final answer:
To install six hard drives using the same cable into a server, SCSI is the required device interface as it allows multiple devices to be connected to a single cable.
Step-by-step explanation:
If you wanted to install six hard drives into a server that were all using the same cable, the device interface you would require is SCSI (Small Computer System Interface). SCSI is a set of standards for physically connecting and transferring data between computers and peripheral devices. SCSI interfaces support daisy-chaining of devices and hence allows multiple devices to be connected to a single cable. While SATA (Serial Advanced Technology Attachment) and IDE (Integrated Drive Electronics) are commonly used for hard drives, they do not support as many devices on a single cable. SATA, for example, typically supports one device per cable. IDE supports two devices per cable using a master-slave configuration. USB is not typically used for internal hard drive connections.