Storage Device Interface Facts

Storage device interfaces allow internal and external devices to interact with the storage device by providing an interface through which information can be transferred. The following table describes the most common storage device interfaces:

Interface / Description
PATA / PATA (also called EIDE, IDE, and ATAPI) is a parallel ATA interface. ATA is the standard interface for transferring data from storage devices such as hard disk drives and CD-ROM drives. PATA:
  • Is the most common and the least expensive interface for hard disks and CD/DVD drives.
  • Allows two devices per channel. Most motherboards include two built-in channels.
  • Use parallel communication (meaning devices share the same data transfer channel).
Some disadvantages of PATA interfaces are:
  • They have a maximum speed of 133 MB/s.
  • Because both devices share the same channel, devices must be configured properly to avoid conflicts.
  • They are being phased out and replaced.

SATA / Serial ATA is computer bus technology primarily designed for transfer of data from a hard disk. SATA:
  • Is the successor to PATA.
  • Uses serial communication (meaning each device is on its own channel).
  • Is faster than PATA.
  • Provides built-in support for disk protection methods.
  • Provides for easy configuration--just connect the device to the SATA port.
  • Supports external devices through the External SATA (also called eSATA) standard. eSATA is faster than USB and Firewire.

SCSI / SCSI (Small Computer System Interface) is a standard for transferring data between devices on internal and external computer buses. Though SCSI devices are most commonly used for tape storage devices and hard disks, they can also be used for devices such as CD-ROM drives, scanners, and printers. SCSI:
  • Is typically used in servers that have high availability and speed requirements.
  • Connects multiple devices onto a single bus or chain.
  • Provides better performance than PATA or SATA.
  • Is relatively difficult to configure. Devices must be configured with a device ID, and the bus must be terminated.
  • Is more expensive than PATA/SATA.

USB/Firewire / You can connect storage devices through the USB and Firewire buses. Storage devices that can be connected to the USB or Firewire bus include:
  • External hard drives and CD-ROM drives.
  • Flash memory card readers.
USB and Firewire devices are highly portable and easy to connect.