Western Digital ships world's highest capacity SATA hard drive

Computerworld - Western Digital announced on Tuesday it's been shipping the industry's first serial ATA (SATA) 3TB internal hard drive for about a week. The new drive passes the previous 2.19TB ceiling due to 4-kilobyte sector sizes.

The new offering, part of WD's Caviar Green family of SATA hard drives, is available in 2.5TB and 3TB capacities utilizing 750GB platters and Advanced Format technology. Advanced Format refers to any drive using sector sizes that are larger than the traditional size of 512 bytes.

WD's Caviar Green 3TB drive

The new drive's 4K sectors allow more bits to be packed onto the surface of the platter.

The industry has been moving toward using 4K drive sectors for more than a decade as advances like perpendicular recording technology allowed hard disk drive capacities to double around every year or so.

The WD Caviar Green 2.5TB and 3TB hard drives run at 5400 RPMs and are designed for use as secondary external storage systems and internal desktop drives in 64-bit systems, meaning the drives will not work with older operating systems like the still widely-used Windows XP.

Newer operating systems, such as Windows Vista, Windows 7 and Mac OS X do support 4K drive sectors.

Linux-based systems require Unified Extensible Firmware Interface (UEFI) firmware to run the new drives. Most new Linux systems are UEFI capable.

The new WD Caviar Green drives are bundled with an Advanced Host Controller Interface (AHCI)-compliant Host Bus Adapter (HBA).

The previous 2.19TB capacity ceiling 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.

In May, Seagate announced that it was working on its first 3TB internal drive, a follow-on the its Constellation ES series of enterprise-class drives. Seagate said today that the drive is not shipping yet.

Seagate senior product manager Barbara Craig told Computerworld a 2.5-in laptop version of the 3TB drive is still in the works, but she declined to say when that drive would be shipping.

Craig said that industry leaders decided in the early 1980s the to limit the LBA range to 16 bits per drive sector because "they never thought we'd go beyond a 2.1TB drive." Software and hardware manufacturers now need to adjust everything from the operating system to the basic input/output system (BIOS) to be able to read larger LBAs, she added.

Without the larger LBA, current operating systems, such as Windows XP, would only be able to access as little as one-third of the space of the new 3TB drive.

There has already been a lot of work done to date to address the LBA limitation, including the creation of a UEFI, which defines how software interfaces with an operating system and the hardware on which it is running on.

Updates to standard hard disk drivers are currently being tested by Seagate and Intel, according to the hard drive maker.

WD Caviar Green 2.5TB hard drives (model number WD25EZRSDTL) and 3TB hard drives (model number WD30EZRSDTL) are available now in the U.S. with a suggested retail price of $189.00, $239.00, respectively. WD Caviar Green hard drives are covered by a three-year limited warranty.

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.

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