SCSI Express is a new interface for solid-state storage that promises the use of the SCSI protocol on the PCIe bus. In this Storage Decisions presentation, Dennis Martin, president of Demartek LLC, explains some of the background of this interface.
"SCSI Express is basically SAS, but for PCI Express," said Martin. "You're carrying the SCSI protocol, all the commands work the same, it's just that you're carrying it over PCI Express rather than a SAS cable."
Martin said this interface is a result of the rise of SSDs and the need for greater bandwidth to take advantage of the technology. According to the Storage Networking Industry Association, SCSI Express' use of two common technologies allows performance gains while "maintaining enterprise experience."
Martin noted that "you're talking gigabytes per second through this interface rather than gigabits per second like you can [get] from SAS."
Martin said SATA Express is a similar concept, and that hard drives don't need this interface speed, but solid state can make use of it. "Not to be outdone, the SATA guys said 'we got a new one, too.' So there's a new one called, 'SATA Express,'" said Martin. "Same idea -- you're going to take the SATA protocol, and run it over a PCIe Express transport."