By Heidi Biggar
Although Serial ATA disk drives are not expected to become widely available until early next year, a variety of vendors have started to introduce products designed around the new specification.
Analysts expect Serial ATA to become a competitive interface for desktop and enterprise systems over the next year or so because of its relatively low cost and improved features. According to Gartner Inc., ATA RAID shipments are expected to increase at a CAGR of 73% through 2005.
Despite a lack of Serial ATA disk drives, a number of controller and subsystem manufacturers have begun shipments. For example, 3ware last month announced a converter kit along with its Serial ATA controller family, the Escalade 8500 series.
The kit allows integrators to connect parallel ATA disk drives to Serial ATA controllers and cabling, providing the benefits of Serial ATA technology, including better performance, increased drive support (up to 12 drives with the 3ware controller), command queuing and reordering, improved reliability (similar MTBF rates to SCSI drives), and simpler configuration, according to Mike Wentz, senior director of engineering at 3ware.
Wentz says that 3ware is seeing initial interest in the Escalade controllers from "white box" system vendors, but he expects RAID vendors to follow suit. "The challenge is getting vendors to realize they can build less expensive and just as, or even more, reliable systems with Serial ATA."
Because 3ware builds its ATA controllers on a point-to-point switch (versus bus) architecture, its parallel ATA customers won't see any change in performance as they move to Serial ATA, says Wentz. "We've already seen our parallel ATA controllers outperform SCSI, [which is] due to the switched architecture," he says. "One on one, SCSI will kill ATA, but if you aggregate drives, ATA can outperform SCSI."
The Escalade 8500 controllers have a throughput of up to 150MBps; support RAID 0,1, 10, and 5 (as well as JBOD); and support 4, 8, or 12 serial or parallel ATA drives per card. Pricing starts at $449.
Elsewhere, Adaptec this summer began sampling a Serial ATA card to server and workstation vendors, and Ci Design last month announced its SR series of storage enclosures for Serial ATA. The enclosures support ATA, SCSI, and Fibre Channel drives and come in 1U 4-drive, 2U 12-drive, and 3U 16-drive configurations.