Toshiba's Storage Device Division (SDD) today claimed it has begun shipping the world's first commercially available hard disc drive (HDD) based on perpendicular magnetic recording (PMR). The newly designed 1.8-inch HDD packs 40Gb on a single platter – the largest single-platter capacity yet achieved in this small form factor, according to the electronics giant.

In terms of data density, the drive boasts 206 megabits per square millimeter (133 gigabits per square inch).

Dubbed MK4007GAL, the device will be used primarily in consumer electronics (CE) devices, enabling users to store up to 10,000 songs or 25,000 photos on a single 40Gb platter.

The technology is based on a newly developed magnetic disk structured to support perpendicular recording, a high-performance perpendicular magnetic head, and disk and head integration technology that maximises their combined performance.

Conventional longitudinal recording stores data on a magnetic disk as microscopic magnet bits are aligned in plane. Although advances in magnetic coatings continue to improve data recording densities on HDD, when the densities become too extreme, the magnetic bits repulse each other due to in-plane alignment. Squeezing more bits on to a disk will eventually reach the point at which crowding degrades recorded bit quality. As such, HDD manufacturers face fast-approaching limits on storage capacities.

By standing the magnetic bits on end, perpendicular recording reinforces magnetic coupling between neighbouring bits, achieving higher and more stable recording densities and improved storage capacity.

Scott Maccabe, vice president, Toshiba Storage Device Division, said: "PMR opens the door to products we haven't even begun to imagine by removing the technical barriers inherent to packing more data on an HDD."

The 1.8-inch PMR HDD is now shipping in Toshiba's newly launched Gigabeat

F41 portable media player.