Hitachi announces storage breakthrough

Hitachi has more to celebrate than the birth of the hard drive, which happened 50 years ago today in San Jose, California. The company is also celebrating an areal density achievement of 345 gigabits per square inch (Gbits/sq. in.) using perpendicular magnetic recording (PMR) technology. This areal density, demonstrated in laboratory testing, represents an increase of more than two-and-a-half times the areal density of today's highest-capacity products.

By 2009, Hitachi predicts that 345 Gbits/sq. in. would result in a two-terabyte (TB) 3.5-inch desktop drive, a 400-gigabyte (GB) 2.5-inch notebook drive or a 200-GB 1.8-inch drive(2). In the first half of 2007, Hitachi expects to bring hard drive areal density half way to the 345 Gbits/sq. in. mark with a 1-TB 3.5-inch product.

With PMR technology rolled out in high-volume production this year -- appropriately on the 50th anniversary of the hard drive -- researchers are looking at overcoming the next obstacles to advancing hard drive technology. The major challenge that hard disk drive designers are facing in increasing data densities is that the magnetic grains on the disk that store the data must become smaller and will eventually become too small to be thermally stable at room temperature. Patterned media and thermally-assisted recording are solutions to this problem.

Today, roughly 100 magnetic grains make up a single bit of data. With patterned media, researchers are creating isolated magnetic islands with one magnetic grain representing a bit of data. By using fewer magnetic grains, patterned media allows more bits of data per square inch of disk space while maintaining thermal stability.

Rather than using fewer grains to represent a bit of data, thermally-assisted recording allows magnetic grains to be smaller while resisting thermal fluctuations at room temperature. As its name suggests, thermally-assisted recording uses a laser to heat up the media while the magnetic head is writing the smaller bits of data. This enables the use of media that is stable at room temperature with the very small magnetic grains required for high-density storage.

Hitachi researchers predict that patterned media technology could ship in products as early as 2010. They believe that thermally-assisted recording would be combined with patterned media technology several years later when patterning alone is insufficient to sustain progress.