After years of talk, Seagate announced about a year ago that its advanced engineering team had developed HAMR (Heat-Assisted Magnetic Recording) “alongside some of the most complex nanoscale recording technologies in order to create the Mozaic 3+ platform, enabling mass-capacity storage gains at unprecedented areal densities of 3 TB/disk and beyond”.
Then, in October Western Digital unveiled its own 32TB hard drive, so you can argue about who got there first, but what matters to the consumer is capacity and reliability.
Seagate’s 32TB hard drive is finally here, albeit with what the company describes as “Limited Availability”.
“As the Data Age emerges, the insatiable hunger for greater storage capacity accelerates at an astronomical rate,” Seagate said. “The capacity of hard drives needs to continue increasing to meet the demands of data growth.
“To increase hard drive capacity, engineers try to fit more data bits, or ‘grains’, onto each disk platter – they increase the density of bits crammed into each square inch of surface space. More bits on a disk means more data can be stored.”
When density is increased, Seagate said, the grains are so close together that the magnetism of one grain and impact the magnetic direction of surrounding grains. That doesn’t sound good, and it isn’t.
“The stability of each grain at normal temperatures (‘thermal stability’) becomes a problem; the only way to fix that is to manufacture the disk platter using new materials that make grains more thermally stable, so the grains will not influence each other,” Seagate said.
But then, although this “makes each bit very stable even at room temperature”, it introduces another challenge: How do you force a very stable bit to change its magnetic direction when you want it to? How do you write new data onto the hard drive, if the grains are thermally very stable?
This is where HAMR comes in, and it all gets a little techy.
“HAMR technology built on the Mozaic 3+ platform solves both these problems. HAMR requires a new media magnetic technology on each disk that allows data bits to become smaller and more densely packed than ever, while remaining magnetically and thermally stable.
“Then, to write new data, a small laser diode attached to each recording head momentarily heats a tiny spot on the disk, which enables the recording head to flip the magnetic polarity of a single bit at a time, enabling data to be written.
“Each bit is heated and cools down in a nanosecond, so the HAMR laser has no impact at all on drive temperature, or on the temperature, stability, or reliability of the media overall.”
