Today's hard-disk drives (HDDs) face a technical chasm known as the superparamagnetic limit, tying them to maximum densities of 130 to 160 Gbits/in.2 Beyond that, the magnetic energy holding the bits in place becomes equal to the disk drive's ambient thermal energy, and data gets scrambled.
Yet the traditional longitudinal recording technique is rapidly approaching this limit, and fast-growing consumer products demand more and more storage. That's why HDD makers are turning to perpendicular recording, which can support much greater densities.
Using this development, Hitachi Global Storage Technologies (GST) has achieved an HDD areal density of 230 Gbits/in2. That's more than twice the density level of HDDs that are presently shipping and well above the superparamagnetic limit.
With the capability to support such a high density, Hitachi GST's perpendicular recording technology could be used to create 1-in. HDDs with storage capacities as high as 20 Gbytes. Meanwhile, Toshiba Corp. also said it will use perpendicular recording in an upcoming line of 1.8-in. HDDs. Other HDD suppliers aren't far behind.
Crossing the superparamagnetic limit will enable HDDs that better address the consumer electronics market, which represents an area of rapid growth for HDD suppliers. Unit shipments of HDDs for consumer applications, mainly for MP3 players, hit record levels in 2004. These HDDs have an insatiable appetite for audio and video storage capacity. With the arrival of perpendicular recording, HDD makers can now satisfy this appetite.
