News

posted on 30 April 2008 10:51

Faster SAS drive arrays are coming: a prototype Hitachi GST 6Gbit/s SAS hard drive has successfully interoperated with PMC-Sierra's 6Gbit/s SAS chipsets.

SAS (serial-atttached SCSI) currently operates at 3Gbit/s. The SAS-2 standard doubles this to 6Gbit/s, meaning around 600MB/sec. PMC-Sierra has previously demonsrated interoperability with Seagate SAS drives.

Storage array designers can now start designing 6Gbit/s SAS arrays with PMC-Sierra chipsets and either Hitachi or Seagate drives. Such arrays will deliver more I/O bandwidth than SAS-1 arrays while being backwards-compatible with them. Since SATA and SAS drives can interface to the same controller then 6Gbit/s SATA is in prospect as well, if the SATA drive manufacturers produce what would be SATA-3 drives.

There is nothing about SATA-III at the Serial ATA website. When it comes it is expected that SATA-III will support the use of several SATA-III devices on a single SATA line.

It would be good to have desktop PCs with such drives instead of the lumbering drives most are shipped with.

PMC-Sierra's 6Gb/s SAS chipsets include the Tachyon SPC 8x6G SAS protocol controller, the SRC 8x6G RAID-on-Chip controller and maxSAS SXP 36/24x6GSec expander switches.

Currie Munce, Hitachi GST's VP for its Enterprise HDD Business Group, said: "The increased transfer rate of the new 6Gbit/s SAS interface is critical to satisfying our enterprise customers' continuing appetite for performance enhancements."

It's probable that 2.5-inch SAS drives will be amongst the first to receive the SAS-2 interface boosting still further the IOPS you can get from a shelf of them.

^{[Paul Roberts, news editor.]}