Seagate has used its perpendicular recording technology in an external drive for the first time. It's transferred its Momentus 2.5inch, 5400rpm, notebook technology to its USB 2.0 Portable Hard Drive line with a 160GB capacity unit.

This is 30 percent up on the current largest capacity model in the range, a 120GB unit. Existing products use longitudinal recording technology in which the magnetised areas of the disk are laid out flat. Perpendicular technology flips then onto one end and stacks them vertically, meaning more data can be stored in the same area.

The products, pocket-sized, weigh less than 1lb and support transfer speeds of up to 480Mbit/s.

Seagate has also launched a 500GB version of its external SATA hard drive, increasing current capacity limits by 100MB. The range uses 3.5 inch platters and longitudinal recording with the 3Gbit/s SATA interface. Theoretically a change to perpendicular recording could increase capacity again, up to 650GB. These external drives are intended for backup purposes and feature a single button press to activate the bundled Bounce Back Express software.

The 160GB Portable Hard Drive will be available in February and will retail for $379 (about £230). The Seagate 500GB eSATA PushButton Hard Drive will be available in April, 2006 and pricing hasn't been announced.