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Seagate ships HAMR tech in new HDDs

Seagate's Mozaic 3+ brings HAMR-based HDDs to market with 3 TB platters, potentially helping to breathe new life into the legacy storage technology.

Seagate launched a line of hard drives that use laser heat technology to store more data on spinning disks, lowering the cost per terabyte when using HDDs.

The new Mozaic 3+ drives utilize heat-assisted magnetic recording (HAMR) technology, which uses a superlattice iron-platinum alloy media to increase the number of bits per square inch and laser heat to stabilize the data stored on disk. The vendor also stated that because of this increase in areal density, the Mozaic 3+ drives are more environmentally friendly as they store more data in a smaller footprint and use less energy per terabyte.

Seagate is the first vendor to ship an HDD with more than 3 TB per platter, and said it plans on only going up from here. In the coming years, the HDD vendor wants to introduce 4 TB and 5 TB platters and plans to bring 50-plus TB drives to market as early as 2028.

This new technology represents a gain in areal density at a more rapid pace than the market saw in the last few years, according to Ed Burns, an analyst at IDC. These gains had slowed as vendors struggled against the limitations of increasing the bits stored in the same form factor, with the same number of components at roughly the same bill of materials costs, he said.

Getting back on the areal density growth curve is the name of the game in hard drives.
Ed BurnsAnalyst, IDC

"Getting back on the areal density growth curve is the name of the game in hard drives," Burns said.

Adding components and complexity to HDDs adds costs, but B.S. Teh, executive vice president and chief commercial officer at Seagate, said a drive-to-drive comparison is shortsighted.

While the cost per drive does go up as the amount of data stored per drive goes up, Mozaic 3+ drives will be purchased in bulk -- mostly by major cloud providers -- and will hit a threshold that makes the cost per terabyte cheaper, Teh said.

Drives using new technology such as lasers also tend to be more expensive, Burns said. But as Seagate approaches 40 TB and 50 TB drives, the increased density will result in better gross margins.

"This allows them to share some of the cost savings with the customer in the form of price discounts," Burns said.

Lasers, magnets and alloys

The Mozaic 3+ combines proprietary Seagate technology including the HAMR technology's plasmonic writer, a nanophotonic laser that temporarily heats up the bit area for a reliable and stable write, according to Teh. He added that there is a secondary source for the lasers, resulting in dual sourcing and better supply.

The bits are written to a superlattice iron-platinum alloy media that allows for more storage of bits on a smaller media grain size. To read data back, Seagate uses a magnetic field reading sensor known as the Gen 7 spintronic reader.

A diagram of how Seagate Mozaic HAMR technology works.
The Seagate Mozaic line brings technology innovation to lower HDD costs.

Controlling it all is Seagate's 12-nanometer system-on-a-chip controller that adds performance compared with the previous 24 nm model.

Seagate's HAMR technology has been in development for years, advancing beyond other HDD vendors, according to Burns.

"Maybe there is an advantage to being a fast follower, but it's a complex technology and more difficult than just copying another drive," he said.

Extending the life of HDDs -- for now

The Mozaic 3+ comes at a time when storage needs are on the rise across the board, according to Burns. It's also a time when other storage technologies such as the more expensive SSDs are making a play for the same market and trying to close the price-to-capacity gap.

"HAMR preserves that gap for longer," he said.

Scott Sinclair, an analyst at TechTarget's Enterprise Strategy Group, said HDDs need to innovate with technologies such as HAMR if they want to keep pace with the demands that massive data growth brings. However, hard drives -- especially large-capacity HDDs -- are more problematic in the event of a drive failure, leading to use case limitations.

"When it gets to that scale, the use cases can narrow as the failure domain changes along with the time to recover data on a single drive," Sinclair said.

Adam Armstrong is a TechTarget Editorial news writer covering file and block storage hardware and private clouds. He previously worked at

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