By Ann Silverthorn
—Hitachi Global Storage Technologies (Hitachi GST) last week began shipping 15,000rpm Ultrastar 15K147 hard disk drives with either Serial Attached SCSI (SAS) or 4Gbps Fibre Channel interfaces. The company claims to be first to market with 4Gbps Fibre Channel drives.
"SAS will replace parallel SCSI," says Sam Sawyer, senior advisor, product planning and strategy, at Hitachi GST, "and SAS [subsystems] will accommodate both SAS drives and SATA [Serial ATA] drives, so you can configure a storage system with very fast drives for online transaction processing types of applications as well as lower-cost 'bulk storage' in the same enclosure."
Sawyer points out that SAS offers much greater connectivity than parallel SCSI. "You can connect 15 drives on a parallel SCSI bus, but a SAS infrastructure will accommodate more than 16,000 connections between drives, HBAs [host bus adapters], and expanders. So, you can get much more complicated configurations, such as SANs, but in a local area."
SAS supports data transfer rates of up to 3Gbps.
The 4Gbps Fibre Channel drives provide a data-transfer rate of up to 400MBps half-duplex and up to 800MBps full-duplex per port.
The new drives are available in 36GB, 73GB, and 147GB capacities on two, three, or five platters and feature 16MB caches. Hitachi GST will continue to offer Ultrastar 15K147 drives with Ultra320 parallel SCSI interfaces.
Other drive specs include an average seek time of 3.3ms to 3.7ms, average latency of 2ms, and 33% more I/Os per second than Hitachi's 10,000rpm drives
Shipments of qualification units began last week. Volume production is expected at the end of July.