Seagate said Monday that it was the first hard-drive maker to reach the terabit density milestone, using a technology that it claims will replace magnetic hard drives in the future.

Seagate said Monday that it was the first hard-drive maker to reach the so-called terabit density milestone, using a technology that it claims will replace magnetic hard drives in the future.

Seagate said it achieved a storage density of 1 trillion bits per square inch using heat-assisted magnetic recording (HAMR), which Seagate sees replacing perpendicular magnetic recording, the technique used in today's hard drives.

If and when HAMR becomes commercialized, a drive with a terabit density would greatly increase the storage capacity of today's hard drives, whose density is about 620 gigabits per square inch.

A terabit drive would equate to a mobile 2.5-inch hard drive storing about 2 terabytes, or a 3.5-inch desktop drive capable of storing 6TB. Today, mobile drives store about 750GB, while desktop drives store up to 3TB. Theoretically, Seagate said, HAMR technology should scale to 5 to 10 terabits per square inch, or 20TB 2.5-inch drives and 60TB 3.5-inch drives.

"The growth of social media, search engines, cloud computing, rich media and other data-hungry applications continues to stoke demand for ever greater storage capacity," said Mark Re, senior vice president of Heads and Media Research and Development at Seagate, in a statement. "Hard disk drive innovations like HAMR will be a key enabler of the development of even more data-intense applications in the future, extending the ways businesses and consumers worldwide use, manage and store digital content."

The technology, which uses lasers to heat the recording medium, was pioneered by the defunct TeraStor Corp. and Quinta, which was acquired by Seagate in 1997. The idea has been to push the so-called paramagnetic limit - beyond which data can not be written reliably, due to bits "flipping" their magnetic polarity and turning data into meaningless noise - farther out.

The problem is that the technology has taken longer than expected to be commercialized. In 2002, it would be 2008 before HAMR could be commercialized. In 2004, Seagate . On Monday, a Seagate spokesman said that HAMR was still several years away.

"We're on track for commercialization around mid-decade," the spokesman said.