Seagate Technology has launched its first 2TB enterprise-class disk drive as part of a new family of near-line SAS and SATA drives.

The new Constellation 2.5 inch and Constellation ES 3.5-inch drives come in Serial-Attached SCSI (SAS) 6Gbits/sec or Serial ATA (SATA) 3Gbits/sec models and include a feature that allows them to shut down when not in use to save power.

Western Digital was the first to release a 2TB drive , but it was a SATA drive aimed at desktop and external storage applications.

WD's 2TB drive uses four 500GB platters, each platter with 400Gbit-per-square-inch areal density. It has a transfer rate of 3Gbit/sec and a 32MB cache. Its suggested manufacturer's retail price is $299 (approx £210).

Seagate's Constellation and Constellation ES models are also four-platter drives rotating at 7,200rpm and aimed at data centre operations. They come with 32GB cache on the SATA model and 16GB cache on the SAS model (download PDF) and will replace Seagate's Barracuda ES enterprise drives.

Seagate did not offer retail pricing on the new drives.

The Constellation drives will be available this quarter in 160GB and 500GB capacities. Constellation ES drives will be available in the third quarter of this year and will offer capacities of 500GB, 1TB and 2TB.

Seagate said it is aiming the new Constellation drives at Tier 2 applications, or near-line storage, which is one level below 15,000rpm Fibre Channel and SAS drives, which are used for primary storage. Seagate's drives will reside in disk arrays and servers that sit between primary storage and tape archive systems.

The fact that the new drives can be powered down using Seagate's PowerChoice firmware when not in use will cut power consumption by up to 54 percent in enterprise environments, Seagate said in a statement.

John Monroe, a vice president of research at Gartner, said the need for devices with greater storage capacity "will continue to expand in multiple directions and dimensions, but there will be an increasing scrutiny of all storage system purchases, with an eye to decreasing power consumption, footprint and cost per gigabyte in unprecedented ways."