Drive advance fuels terabyte era

A single hard drive with four terabytes of storage (4TB) could be a reality by 2011, thanks to a nanotechnology breakthrough by Japanese firm Hitachi.

The company has successfully managed to shrink the read-write head of a hard drive to two thousands times smaller than the width of a human hair.

The smaller head can read greater densities of data stored on the disk.

Hitachi said the advance would fuel the "terabyte era", with a 4TB drive able to hold more than a million songs.