Western Digital has achieved 520 Gb/in2 areal density - the hard drive industry's highest demonstrated density to date using continuous media.

The company revealed the milestone this week at the Perpendicular Magnetic Recording Conference in Tokyo after an earlier demonstration in California.

Following WD's growing investments in technology the past five years, the company achieved 520 Gb/in2 using its own perpendicular magnetic recording (PMR)/tunneling magneto-resistive (TuMR) head technology. This level of density produces a 3.5-inch hard drive storing 640 GB-per-platter and single hard drive capacities as large as 3 TB. Based on the industry's current density growth rate of more than 40 percent per year, those capacities are expected to be available in the 2010 timeframe.

Current industry-leading hard drive densities shipping in high volume are about 200 Gb/in2, as featured in WD's 250 GB WD Scorpio 2.5-inch drive for notebooks and mobile applications, which began shipping in May 2007.

WD demonstrated 520 Gb/in2 density in its Magnetic Head Operation labs in Fremont, Calif., earlier this month. "The milestone was realized using our current-technology MgO reader, illustrating the extendibility of PMR-TuMR head technology generations into the future," said Hossein Moghadam, chief technology officer for WD.

At the same event, Japanese Hitachi announced a technology related to the CPP-GMR hard disk heads, which are expected to enable hard disk drive (HDD) recording densities of one terabit per square inch (Tb/sq. in.).