IBM has broken the data density record for hard drives with a technology the company calls Pixie Dust.

IBM is already despatching samples of the drive, the 4,200 Travelstar 80GN, and expects to ship this in 2003. Its current capacity is 80GB.

The density with which data can be packed together on the surface of the new drive, called areal density, is 70G bits per square inch (bpsi), revealed IBM.

Because hard disk drives are built to a common size, it is not possible to increase storage capacity by adding physical storage space. Engineers need to develop technologies that allow more data to be crammed into the available space.

IBM's Pixie Dust sandwiches a three-atom-thick layer precious metal (ruthenium) between two magnetic layers. This allows the company to increase areal storage density. IBM has advanced this technology by introducing a five-atom-thick version of Pixie Dust. The company is aiming to reach an areal density of 100G bpsi by 2003.

Toshiba and Fujitsu have achieved areal densities of 52G bpsi and 53.2G bpsi respectively.

IBM also announced plans for a new class of Travelstar mobile hard-disk drives with rotational speeds of 7,200 revolutions per minute (rpm). That compares to the 5,400rpm speed of IBM's current fastest mobile disk drives and is similar to the speed of drives found in most desktop computers.

All three speeds will benefit from the enhanced Pixie Dust technology, IBM said.