HAMR works on the principle that, when heated, a disk's magnetic materials can hold more data in smaller spaces, such that you can fit more overall data on the drive. It's not just putting a tiny hot plate inside an HDD chassis; as Seagate explains in its technical paper, "the entire process—heating, writing, and cooling—takes less than 1 nanosecond." Getting from a physics concept to an actual drive involved adding a laser diode to the drive head, optical steering, firmware alterations, and "a million other little things that engineers spent countless hours developing." Seagate has a lot more about Mozaic 3+ on its site. //

There is no price yet, nor promise of delivery, but you can do some wishful thinking on the product page for the Exos M, where 30 and 32TB capacities are offered. That's 3TB per platter, and up to three times the efficiency per terabyte compared to "typical drives," according to Seagate. Seagate has previously boasted that its Mozaic 3+ HAMR drives, under "aggressive field use stress tests," have seen more than seven years of head life.

Western Digital has its own 32TB drive, based on energy-assisted perpendicular magnetic recording, or e-PMR. Both companies have suggested their high-capacity drives are ideal for AI model training, given the gargantuan storage demands and energy pull of that job. Toshiba intends to move into the HAMR drive space, which accounts for all three of the major HDD makers' plans.