Not to be outdone by Hitachi's breakthrough in hard disk drive technology that could see storage capacity rise to 4TB by 2011, Western Digital has claimed to have created the world's highest density hard drive platter, hitting 520Gb per square inch - more than double today's typical data density of 200Gb per square inch.

The company achieved the higher density using its own perpendicular magnetic recording (PMR)/tunneling magneto-resistive (TuMR) head technology, touting "the extendibility of PMR-TuMR head technology generations into the future," even though earlier this week Hitachi said that the technology wouldn't be up to the task of reading data off a 500Gb per square inch platter.

According to WD, this level of density produces 3.5-inch hard drives capable of storing 640 GB-per-platter and, based on the industry's current density growth rate of more than 40 percent per year, the company says we can expect 3TB hard drives "in the 2010 timeframe."