Solid state disks are slowly gaining ground on traditional hard drives, particularly in laptops, but that isn’t stopping Hitachi from continuing to push HDDs to the limit. While recent developments in the field are already yielding one terabyte units, Hitachi believes they can have a commercial 3.5-inch hard drive on the market that can hold 5TB by 2010.

The company aims to achieve this boost in capacity with write heads that use something called current perpendicular-to-the-plane giant magnetoresistance (CPP-GMR), which pushed data density above one terabit per square inch. But it seems that Hitachi isn't the only one that is considering the release of a 5TB hard disk, Fujitsu also has some plans of their own – though fewer details on the technology used to achieve this have been made available.