Toshiba has pushed its hard disk drive technology up a level with the unveiling of a 2.5in drive that has the industry's highest capacity per platter, the company announced this week.

The new drive has an areal density of 48.8Gbpsi (gigabits per square inch). This translates into a storage capacity of 30GB on each 2.5in platter. The new drive has two platters for a total capacity of 60GB, according to a Toshiba statement.

The new technology benefit users in one of two ways. Drives holding 60GB are already available, but the greater storage density means that Toshiba can build drives with fewer platters, making them around 25 percent thinner and 50 percent lighter than existing units.

The 2.5in drives are commonly used for mobile devices such as notebook PCs, although companies have recently begun using them in other types of mobile devices, such as SonicBlue's Rio Riot digital music player and consumer electronics products such as digital video recorders.

Following this trend, a removable hard-disk technology has been also developed by Canon, Fujitsu, Hitachi, Phoenix Technologies, Pioneer, Sanyo, Sharp and JVC. Toshiba has also demonstrated prototypes of such a system.

The new Toshiba drive has a maximum rotational speed of 4,200rpm, data transfer rate of 100MB per second and average seek time of 12 milliseconds.

Toshiba starts sample unit shipping this week and plans mass production in late May, it said.

At R&D level, Toshiba has already demonstrated a prototype drive with an areal density of 52Gbpsi on a 2.5in drive and hopes to achieve 100Gbpsi before the end of 2003.