In November, Compaq, IBM, LSI Logic, Maxtor, and Seagate formed a consortium to develop a serial-attached point-to-point SCSI (Serial SCSI) specification that the group says will complement Serial ATA in entry-level server markets. Analysts view the proposal as an effort to counteract Serial ATA in traditional enterprise SCSI markets.
The Serial SCSI specification will reportedly leverage both SCSI and Serial ATA standards, which consortium officials say will enable users to seamlessly run a variety of serial-attached storage devices together. The idea, they say, is to build a specification that not only meets the industry's requirements for more-flexible storage I/O systems, but also improves on the reliability and cost-efficiencies of previous SCSI generations.
Toward that end, the consortium says it plans to develop a single backplane that will accommodate either Serial ATA or Serial SCSI. "The idea is to build one cable so customers don't have to commit to either technology until the device goes out the door," explains Harry Mason, director of industry marketing at LSI Logic.
So, why serial-attached and not another generation of parallel SCSI? We've pushed parallel SCSI about as far as we can, explains Mason. "Every time you up the frequency or up the bus speed, you have to share bandwidth, and that changes the characteristics of the bus. At some point, you get to the point of diminishing returns."
Consortium members hope to hand over a working specification to the SCSI Trade Association (www.scsita.org) by mid-year. Product demonstrations are currently slated for 2003, with product delivery in 2004. The interface will premiere with a 150MBps or 300MBps transfer rate, depending on where Serial ATA is on its evolutionary curve.