Serial Attached SCSI and Serial ATA Compatibility (PDF)
Written by Intel, this white paper is targeted to IT managers and anyone who is interested in learning more about the compatibility between Serial Attached SCSI and Serial ATA. The two technologies were defined with compatible physical layers so they can operate in the same Serial Attached SCSI system.

SCSI is the dominant disk interface technology in enterprise storage today, with ATA emerging in many
entry-level systems. Some enterprise solutions utilize both standards, but the inherent differences between SCSI and ATA technologies require most of them to implement two separate storage subsystems – one for SCSI and one for ATA. As disk interconnect speeds continue to rise, existing SCSI and ATA buses are reaching their practical performance limits. New interconnect technologies are
needed with roadmaps that can meet performance requirements going forward. Serial Attached SCSI and
Serial ATA interfaces are emerging as solutions to these problems. Serial Attached SCSI is a serial version of SCSI, while Serial ATA is a serial version of ATA. Both technologies preserve existing investments in SCSI and ATA software applications. Serial Attached SCSI is being developed to maximize compatibility with Serial ATA, enabling a single storage subsystem to accept either Serial Attached SCSI or Serial ATA hard drives. This results in unprecedented flexibility to select the drive type that is most appropriate for a particular application as well as reducing the overall solution cost. This paper presents
an overview of the benefits of Serial Attached SCSI and Serial ATA compatibility in enterprise environments.