Serial Attached SCSI Moves Closer to Reality

Maxtor, Seagate, and LSI have announced the first Serial Attached SCSI (SAS) data transfers directly to disk, paving the way for the debut of the first SAS products later this year.

Maxtor says it achieved full speed, 3Gb/s operation between an LSI Logic SAS controller and an in-form-factor prototype Maxtor SAS disk drive with dual
active ports. Using the LSI Logic SAS1064 controller IC, Maxtor completed simultaneous read and write operations on both ports and verified 3Gb/s SAS I/O transfers, in accordance with the SAS protocol and standards.

Maxtor says it integrated several key technologies to achieve the milestone, including enabling queued read, write, and compare commands across the SAS interface, and reading and writing data to and from the media.

Dual ports provide two separate data paths to the drive, allowing for higher levels of performance and eliminating a single point of failure, making the technology a natural for highly-available enterprise storage systems.

Kevin Wittmer, director of technical marketing at Maxtor, told Enterprise Storage Forum that the fully integrated ASIC solution is one of the first to write data “all the way to disk and read it back, not just to buffer.” It moves the company closer to its goal of providing “serial storage in a box,” he says.

Wittmer adds that he expects SAS products to become available in the second half of the year.

Since SAS backplanes also support Serial ATA (SATA) drives, users can have one platform “and plug in whatever disk makes the most sense for the application,” he says. IT managers can use SATA drives for applications requiring the maximum capacity at the best cost and SAS drives for performance-oriented applications that require high transaction rates.

Seagate, LSI Plan SAS Demo

Seagate Technology and LSI Logic plan what they claim will be the “first public demonstration of Serial Attached SCSI dual-port and 3Gb/s transfer rates using the world’s first 2.5-inch enterprise disk drives and LSI Logic SAS1064 controller ICs.”

The booth demonstrations at the Intel Developer Forum in San Francisco will begin today.

Seagate plans its first SAS products this Fall, and LSI Logic is developing SAS controllers, expanders, host bus adapters (HBAs), and RAID and ROMB (RAID on motherboard) storage adapter solutions.

Seagate will feature systems at the forum consisting of LSI Logic SAS host bus adapters transmitting data at 3Gb/s with Seagate’s 2.5-inch enterprise disk drive.

“With dual-port capability, the demonstration showcases a key differentiator between SAS and SATA drives,” the companies say. “In enterprise environments that demand reliability, high-availability, and performance, dual port is an essential feature to ensure a stable system environment as well as to enable
added performance for Direct Attached Storage (DAS) subsystems.”

LSI Logic will host a companion demonstration where the companies will feature multiple SAS and Serial ATA disk drives, as well as SAS protocol compliance.

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