Even though solid-state drives are considered to be the future of data storage, they won't render hard disk drives obsolete anytime soon as they still can't compete on a cost-per-bit basis yet. To that end, Hitachi, the first disk manufacturer to break the 1TB consumer disk drive barrier through Perpendicular Magnetic Recording, continues to make advances on the HDD front and has recently announced a breakthrough in hard disk drive technology that could see storage capacity rise to 4TB by 2011.

The increase has been made possible by shrinking the size of the hard disk's read head to the 30nm-50nm range with the new "current perpendicular-to-the-plane giant magneto-resistive" (CPP-GMR) technology, achieving more than a four-fold increase in storage density.

Recording heads with 50nm track widths are expected to debut in commercial products in 2009, while those with 30nm track widths will be introduced two years later.