At the Perpendicular Magnetic Recording Conference in Tokyo, Western Digital has demonstrated hard-disk drive technology with a storage-area density of 520 Gigabits per square inch, allegedly the highest to date. The company's perpendicular magnetic recording/tunneling magneto-resistive head technology produces a 3.5-inch hard drive storing 640 GB-per-platter and single hard-drive capacities up to 3 TB. Based on the industry's current density growth rate of more than 40 percent annually, those capacities are expected to be available in the 2010 timeframe. The company's current hard-drive densities are reportedly in the range of 200 Gigabits per square inch. Its 250-GB WD Scorpio 2.5-in. drive for notebook computers and mobile applications, for example, began shipping in May 2007.