Seagate sampling 36 TB HAMR disk drive

Seagate is pushing out its capacity leadership position on Toshiba and Western Digital by sampling an Exos M 36 TB disk drive using its HAMR technology, currently the highest capacity disk drive in the industry.

It announced last month that it had been given the qualification all-clear from a top cloud service provider (CSP) to start volume manufacturing and shipping of its Exos M 32 TB HAMR technology shingled magnetic recording (SMR) drive and has now upped HAMR capacity by another 4 TB. The HAMR Mozaic 3+ technology involves a laser momentarily heating a bit area in the disk’s recording medium coating to allow its magnetic polarity to be set by the drive’s write head, before cooling to room temperature when the bit setting will be stable.

Dave Mosley, Seagate
Dave Mosley

CEO Dave Mosley stated: “We’re in the midst of a seismic shift in the way data is stored and managed. Unprecedented levels of data creation – due to continued cloud expansion and early AI adoption – demand long-term data retention and access to ensure trustworthy data-driven outcomes … Seagate continues to lead in areal density, sampling drives on the Exos M platform of up to 36 TB today. Also, we’re executing on our innovation roadmap, having now successfully demonstrated capacities of over 6 TB per disk within our test lab environments.” 

Dell’s Travis Vigil, SVP, ISG Product Management, added: “Dell PowerScale with Seagate’s HAMR-enabled Mozaic 3+ technology plays a crucial role in supporting AI use cases like retrieval-augmented generation (RAG), inferencing, and agentic workflows. Together, Dell Technologies and Seagate are setting the standard for industry-leading AI storage innovation.”

Competitors Toshiba and Western Digital use variations of microwave-assisted magnetic recording (MAMR) to store bits on a recording medium that does not support such small bit areas as HAMR. This means that their disk platters have a lower areal density than Seagate’s HAMR drives, which have now reached 3.6 TB/platter with the company’s ten-platter design. As WD’s capacity tops out at 32 TB and it has an 11-platter design, its areal density is 2.91 TB/platter, 19 percent less than Seagate.

Toshiba’s maximum SMR capacity is 28 TB with its ten-platter MA11  drives, meaning a 2.8 TB/platter rating, worse than Western Digital’s areal density and 22.2 percent less than Seagate.

Both WD and Toshiba have said they will move to HAMR technology. In 2022, Toshiba said it had 40-plus TB HAMR drives, in the FY 2026 period or later, featuring in its roadmap. Seagate intends to introduce second-generation 40 TB HAMR drives in the second half of this year. Given that Toshiba customers need to qualify its HAMR drives and that Seagate has found producing the drives with an acceptable manufacturing yield and reliability a multi-year process, Toshiba could start HAMR drive general availability in 2027. That’s two years behind Seagate.

Western Digital also has HAMR tech introduction plans. It was 12 to 18 months away in June 2023, according to CFO Wissam Jabre. It is now 18 months since then and WD’s HAMR tech has not arrived. Coincidentally, Jabre has just resigned.

Like Toshiba, WD will find HAMR drives need lengthy manufacturing development and also customer qualification, especially by reliability-conscious CSPs and hyperscalers, who will be the largest customers for these nearline, 7,200 rpm drives. WD could find itself 12 months or more behind Seagate when it does move to HAMR.

The Exos M 36 TB drive has a 6 Gbps SATA interface. Seagate has not yet released details such as its sustained transfer rate, cache size, MTBF number, and so forth. We expect these to arrive in a few weeks’ time and be pretty similar to its existing Exos MA11 32 TB drive, positioning Seagate for a more than 12-month capacity advantage.