Tiny Mini Drives

Research work by Hitachi could mean the introduction of one-inch hard drives holding 60Gb instead of up to the 10Gb maximum currently available. Hitachi has said it can fit 230 gigabits of data per square inch on a disk using "perpendicular recording".

Currently the storage industry currently makes hard drives using longitudinal recording, which is reaching its limit. The biggest problem hard drive technology faces is what is called the superparamagnetic effect – when microscopic magnetic grains on the disk get so tiny that they interfere with one another. Perpendicular recording methods overcomes the problem and aligns data bits vertically, perpendicular to the disk. This means more space on a disk for more data and so higher recording densities can be achieved.

Hitachi said it would start using perpendicular
recording in the next generation of its products, in 2007, but it said
its true potential would be realised in the 200 plus gigabit per square
inch range.

BBC News Article
Hitachi