Seagate has jumped to the SATA 2.5 spec, offering twice-as-fast data transfer in a new line of Barracuda hard drives.

SATA2.5 provides 3Gbit/s, while the existing SATA 1.0 spec is rated at 1.5Gbit/s. The new drives are intended for SATA-based servers, meaning not enterprise-class systems, and mid-range to high-end PCs. Seagate said applications might include digital video editing and production, CAD/CAM, and data and image analysis.

The Barracuda 7200.9 family can hold from 80GB to half a terabyte of data (500GB) and spin at 7,200rpm. It has Native Command Queuing (NCQ) which alters the order of access requests to minimise head movements. SATA 2.5 will only deliver the rated bandwidth of 300Mbit/s when the drive head is not moving. To this extent it is like an automatic rifle which can fire rounds at a rate of 2,000 per minute - but only has 150 bullets in its magazine.

However each data transaction will get to and from the disk that much quicker, meaning that accessing servers need spend less time on disk I/O. Seagate's interface supports Intel hyper-threading which will help servers run faster again. Technically the SATA 2.0 spec does not necessarily mean 3Gbit/s transfers.

The Barracuda drive can store up to 160GB on a single platter, which Seagate claim's is the industry's highest available areal density. Perpendicular recording is not yet being used for these drives. When it does they will offer even higher areal densities.

Maxtor has also announced SATA 2.5 drives. Its MaXLine III is for enterprise ATA applications and the DiamondMax 10 is for desktop use. They spin at 7,200rpm, but only hold up to 300GB, and will ship later this quarter.