Seagate Reaches 1Tb Per Square Inch Milestone In Hard Drive Storage

Seagate Promises 60TB Hard Drives Next Decade

by Anton Shilov
03/19/2012 | 03:21 PM

Seagate Technology has become the first hard drive maker to achieve the milestone storage density of 1Tb per square inch, producing a demonstration of the technology that promises to double the storage capacity of today’s hard drives upon its introduction later this decade and give rise to 3.5” hard drives with capacity of up to 60TB over the 10 years that follow.


Seagate reached the landmark data density with heat-assisted magnetic recording (HAMR), the next- generation recording technology. The current hard drive technology, perpendicular magnetic recording (PMR), is used to record the spectrum of digitized data – from music, photos, and video stored on home desktop and laptop PCs to business information housed in sprawling data centers – on the spinning platters inside every hard drive. PMR technology was introduced in 2006 to replace longitudinal recording, a method in place since the advent of hard drives for computer storage in 1956, and is expected to reach its capacity limit near 1Tb per square inch in the next few years.

“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. 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,” said Mark Re, senior vice president of heads and media research and development at Seagate.

Hard drive manufacturers increase areal density and capacity by shrinking a platter’s data bits to pack more within each square inch of disk space. They also tighten the data tracks, the concentric circles on the disk’s surface that anchor the bits. The key to areal density gains is to do both without disruptions to the bits’ magnetization, a phenomenon that can garble data. Using HAMR technology, Seagate has achieved a linear bit density of about 2Mb per inch, once thought impossible, resulting in a data density of just over 1Tb per square inch – 55% higher than today’s areal density ceiling of 620Gb per square inch.

The maximum capacity of today’s 3.5” hard drives is 3TB, at about 620Gb per square inch, while 2.5” drives top out at 750GB, or roughly 500Gb per square inch. The first generation of HAMR drives, at just over 1 terabit per square inch, will likely more than double these capacities – to 6TB for 3.5” drives and 2TB for 2.5” models. The technology offers a scale of capacity growth never before possible, with a theoretical areal density limit ranging from 5 to 10Tb per square inch – 30TB to 60TB for 3.5” drives and 10TB to 20TB for 2.5” drives.