In an unexpected announcement during their quarterly earnings call this week, Western Digital revealed that it has begun sampling an upcoming 32TB hard drive. The nearline HDD is aimed at hyperscalers, and relies on a combination of Westen Digital's EAMR technology, as well as shingled magnetic recording (SMR) technology to hit their highest capacity figures to date.

Western Digital's 32TB HDD uses all of the company's most advanced technologies. Besides energy-assisted magnetic recording (EAMR/ePMR 2 to be more precise) technology, WD is also leveraging triple-stage actuators for better positioning of heads and two-dimensional (TDMR) read heads, OptiNAND for extra performance and reliability, distributed sector (DSEC) technology and a proprietary error correcting code (ECC) technology. And, most importantly, UltraSMR technology to provide additional capacity.

"We are shipping samples of our 32TB UltraSMR/ePMR nearline hard drives to select customers," said David Goeckeler, chief executive of Western Digital, at the earnings call. "These drives feature advanced triple-stage actuators and OptiNAND technology which are designed for seamless qualification, integration and deployment in hyperscale cloud and enterprise data centers while maintaining exceptional reliability."

Seagate is currently shipping its 30TB Exos HDDs based on heat-assisted magnetic recording (HAMR) platform called Modaic 3+ to select exascalers, and the company has implied that it can build a 32TB version of the drive using SMR. Therefore, from capacity point of view, Western Digital's announcement means that the company has caught up with its rival.

As with the comapny's other UltraSMR drives, the 32TB nearline drive is aimed at WD's enterprise customers, whose infrastructure can handle the additional management requirements that SMR imposes. As SMR in enterprise drives is not transparent, it's up to the host to manage many of the complexities that come with a hard drive that isn't suited for random writes. Though at least in WD's case, the upshot is that UltraSMR also offers a more significant density increase than other SMR implementations, using a larger number of SMR bands to increase HDD capacity by up to 20%.

Working backwards, that 20% capacity increase also means that WD's new drive is starting from 2.56TB CMR platters. And while 2.56TB makes for a very decent areal density, this would mean that WD is still behind rival Seagate in terms of areal density overall, as Seagate has 3TB CMR platters in its latest HAMR-based Exos drives.