Seagate on Wednesday introduced the industry’s first hard disk drive (HDD) platform that uses heat-assisted media recording (HAMR). The new Mozaic 3+ platform relies on several all-new technologies, including new media, new write and read heads, and a brand-new controller. The platform will be used for Seagate’s upcoming Exos hard drives for cloud datacenters with a 30TB capacity and higher.
The Mozaic 3+ Platform
Heat-assisted magnetic recording is meant to radically increase areal recording density of magnetic media by making writes while the recording region is briefly heated to a point where its magnetic coercivity drops significantly.
Seagate’s Mozaic 3+ uses 10 glass disks with a magnetic layer consisting of an iron-platinum superlattice structure that ensures both longevity and smaller media grain size compared to typical HDD platters. To record the media, the platform uses a plasmonic writer sub-system with a vertically integrated nanophotonic laser that heats the media before writing. Because individual grains are so small with the new media, their individual magnetic signatures are lower, whereas magnetic inter-track interference (ITI) effect is somewhat higher. As a result, Seagate had to introduce its new Gen 7 Spintronic Reader, which features the “world’s smallest and most sensitive magnetic field reading sensors,” according to the company.
Because Seagate’s new Mozaic 3+ platform deals with new media with a very small grain size, an all-new writer, and a reader that features multiple tiny magnetic field readers, it also requires a lot of compute horsepower to orchestrate the drive’s work. Therefore, Seagate has equipped with Mozaic 3+ platform with an all-new controller made on a 12nm fabrication process. This controller is three times more powerful than its predecessors, according to the company. Seagate did not disclose the number and type of processing cores it uses for the controller or its transistor count, but, being a RISC-V supporter, the company might be using its own custom cores to control its HAMR HDDs.
“The Mozaic 3+ platform represents more than just HAMR technology,” said Seagate CEO Dave Mosley. “It comprises several industry-first innovations that we have integrated to help us scale areal density.”
Seagate implies that its Exos hard drives based on the Mozaic 3+ platform are drop-in compatible with existing cloud servers. In addition to higher capacity, these drives also enable considerably higher sequential read and write speeds, and reduce power consumption per TB. However, they also lower IOPS per TB performance, which will require their users — such as cloud server providers — to mitigate this somehow in a bid to make these HDDs compliant with their quality-of-service (QoS) and other requirements.
Shipping This Quarter, Addressing Many Applications
Seagate said that its Exos hard drives featuring 30TB and higher capacity points would ship in volume later this quarter after the company’s clients complete their qualifications of the new HDDs. In addition, HAMR-based Mozaic 3+ storage technology will enable a wide range of products — including enterprise HDDs, NAS drives, and video and imaging applications (VIA) markets. This means that IronWolf and SkyHawk HAMR-powered HDDs are planned.
“As AI use cases put a premium on raw data sets, more companies are going to need to store all the data they can. To accommodate the resulting masses of data, areal density matters more than ever,” Mosley said.
The industry has worked on HAMR technologies for decades and it is believed that it will enable drives featuring capacities of 80TB — and maybe higher. It remains to be seen when other hard drive makers, such as Toshiba and Western Digital, will follow — but, for now, Seagate has an indisputable lead in HAMR.
Seagate is also working on its Mozaic 4+ platform that will enable 40TB+ HDDs and is due in a couple of years (2026), as well the Mozaic 5+ platform that will power 50TB+ hard drives and will launch in 2028 or later.
For now, Mosley says Seagate is “the world’s only hard drive manufacturer with the areal density capability to get to 3TB per platter and with 5TB on the horizon.”
