Seagate ships 3TB desktop drive, breaking 2.1TB barrier

Computerworld - Seagate Tuesday released its highly anticipated 3TB desktop hard disk drive, the 3.5-in Barracuda XT, thus eliminating the need to purchase extra hardware or software to overcome the previous 2.1TB drive barrier.

Last spring, Seagate had said it would ship its first 3TB HDD, the Constellation ES, by the end of 2010. That drive, for data center servers, has yet to ship.

Western Digital came out with its first 3TB internal desktop drive in January, the Western Digital Caviar Green. Western Digital had its own workaround for the 2.1TB limitation: a HighPoint Rocket 620 internal half-height SATA card, which it ships with the 3TB drive. The card has two SATA 3.0 ports and handles the emulation, if needed, to allow software to work with the larger 3TB hard drive.

Seagate said it was able to make the drive's capacity available to PC systems through its free DiscWizard utility. Seagate added a virtual device driver to the utility to allow legacy BIOSes and OSes, such as Windows XP, to access capacity above 2.1TB on a drive. Without the driver, PCs with older OSes and BIOS designs would only be able to create volumes up to 2.1TB.

Hence, the Barracuda XT hard drive now delivers the highest available capacity on a single drive for home servers and workstations, high-definition video editing and production systems, high-performance PC gaming systems and desktop PCs.

The Barracuda XT 3.5-in hard drive

The new DiscWizard software is available for free download on Seagate's website.

The 2.1TB ceiling for internal HDDs was set about 30 years ago when a decision was made to limit the logical block address (LBA) range on a hard drive. The LBA specifies where blocks of data are stored on a hard drive.

Legacy PC BIOS designs and device drivers and older operating systems such as Windows XP are incapable of using hard drive capacities beyond 2.1TB. The upshot is that computers with older platforms can create partitions with up to 2.1TB of storage capacity, but must be deployed with additional software or hardware and may also require extra device drivers to overcome this limitation.

Currently, in order for PCs to recognize drives with more than 2.1TB capacity, they must use the Unified Extensible Firmware Interface (UEFI) standard that Intel and IBM introduced in 2007. The UEFI standard, however, has not been widely adopted.

"We believe UEFI will remain in a nascent category for a bit longer before there is broad adoption," said David Burks, marketing director for Seagate. "We felt strongly that we needed to create a product that didn't require UEFI for customers who wanted to use the full capacity of these big drives."

Burks admits that UEFI will eventually be the solution across the industry for allowing older OSes and system BIOS to utilize high-capacity drives, and that the new firmware upgrade on DiscWizard is merely a "stop gap" measure for now.

Users can install the Barracuda XT in their PCs the same as any other drive, using Windows to format and partition the drive.

If the systems platform is Windows XP, it will only access 900GB of capacity on the drive - the portion above 2.1TB. Windows Vista and Windows 7 will recognize 2.1TB capacity on the drive. Users will then be required to download and install the DiscWizard firmware.

Once installed, the user interface will show two partitions, one with 2.1TB and the other with 900GB capacity, and allow a user to adjust those partition sizes to their individual needs. Users will not be able to create a single 3TB partition.

The new Barracuda XT differs little from its 2TB predecessor. The only real difference is that the drive has five disk platters versus four. Like its predecessor, the Barracuda XT has a 7200rpm spindle speed and uses the serial ATA (SATA) 3.0 interface specification giving it 6Gbit/sec throughput.

The drive's 64MB cache also adds to its performance.

The drive's suggested retail price is $274.

Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and health care IT for Computerworld. Follow Lucas on Twitter at @lucasmearian, or subscribe to Lucas's RSS feed . His e-mail address is lmearian@computerworld.com.

Read more about Data Storage in Computerworld's Data Storage Topic Center.