By Heidi Biggar
Seagate Technology this week became the first disk drive manufacturer to announce plans for a Serial ATA product family. The company says it will offer a native Serial ATA interface as an option to its new Barracuda ATA V drive this fall. The drive, which is a 60GB-per-platter hard disk drive, will first ship with an Ultra ATA/100 interface next month. Seagate and Intel demonstrated the technology at PC Expo this week.
Seagate is positioning the drive in the network-attached storage (NAS) and entry-level server markets, as well as on the desktop for high-performance PCs and home entertainment devices.
Analysts expect Serial ATA drives to make significant headway into traditional SCSI markets, including low-end networked storage and low-end servers. According to International Data Corp., Serial ATA will account for nearly 100% of total ATA shipments by 2005, or approximately 10 million drives. This compares to about 12.5 million drives for SCSI and 5 million drives for Fibre Channel in the same period.
Seagate's Barracuda ATA V is a two-platter 120GB, 7,200rpm drive with a 570Mbps internal data rate and a 9ms seek time. The Ultra ATA/100 drive will have a 2MB cache, the Serial ATA model 8MB. Company officials say the Ultra ATA/100 drive will be priced higher than its current 80GB option ($129 retail), but lower than competitive multi-platter 120GB offerings. The Serial ATA option is expected to be priced slightly higher than the Ultra ATA/100 model.
Seagate claims that by using a native Serial ATA interface instead of a "bridge" architecture, users will be able to realize the full 150MBps data-transfer rate. Company officials claim that bridge drives, which have to translate parallel data streams into serial data streams (and therefore may be limited by the speed of the controller), may offer lower data-transfer rates than native Serial ATA drives.
Serial ATA is said to offer significant benefits over parallel ATA, including simpler and easier connectivity, improved reliability, and better system expandability.
For more information about Serial ATA and other interfaces (e.g., Serial-attached SCSI), see the upcoming July Special Report in InfoStor, "Countdown to Serial: Helping end users weigh their interface options."