Fujitsu is planning to sell 2.5-in. hard disk drives with a capacity of 200GB in the first half of 2007.

The disks, intended for use in notebook PCs, will consist of two disk platters that will store up to 100GB each, for a total of up to 200GB. The largest capacity 2.5-in. drives the company currently sells store 120GB, said Fujitsu spokesman Fred Hirose.

The higher capacity will be achieved through the use of perpendicular recording technology in the new disks, Fujitsu said.

Perpendicular recording is a method of storing information using magnetic fields to represent each bit. In disks that are commercially available today, the bits, or magnetic fields, lie flat on the disk surface. In drives using perpendicular recording, the bits stand upright. Because they take less space when they stand upright, more bits can be packed on a disk using perpendicular recording, so more recording capacity is available.

The number of bits that can be crammed into a certain amount of space is called areal density, which is expressed in bits per square inch. The Fujitsu disks using perpendicular technology will have areal densities of around 150Gb per square inch, the company said. Its current 2.5-in. notebook drives have an areal density of 105Gb per square inch, Hirose said.

Fujitsu is the fourth major hard disk maker to have announced plans to sell drives using perpendicular technology. Toshiba said late last year that it will start selling 1.8-in. drives using the technology in the middle of this year. Earlier this month, Hitachi Global Storage Technologies said it was testing a 100GB, 2.5-in. drive; and Seagate Technology has said it would start selling drives using the new technology later this year.