Western Digital matches Seagate’s 32 TB HAMR capacity with 11-platter ePMR HDDs

Ashley Gorakhpurwalla, Western Digital
Ashley Gorakhpurwalla, Western Digital

Western Digital has matched Seagate’s 32 TB HAMR disc capacity by adding an 11th platter to its conventional disk drives.

Seagate has developed heat-assisted magnetic recording (HAMR) technology for smaller bit areas using a more coercive and stable magnetic recording medium, with laser-created heat used to help change the magnetic polarity of the bit area, thereby writing the binary data. It is making 30 TB Exos 30 drives and 32 TB shingled (overlapping write track) drives, each with ten platters, using HAMR technology, although these are not yet shipping, being still in a qualification phase.

Ashley Gorakhpurwalla, Western Digital
Ashley Gorakhpurwalla, Western Digital

This has allowed Western Digital to claim it “is now shipping the world’s highest capacity UltraSMR HDD with up to 32 TB leveraging the time-tested, reliable energy-assisted PMR (ePMR) recording technology for hyperscalers, CSPs, and enterprises … with the world’s first commercially available 11-disk design.” 

Ashley Gorakhpurwalla, EVP and GM of Western Digital’s HDD business unit, stated: “Our CMR and UltraSMR technology isn’t just breaking records – it’s giving customers the efficiency and TCO benefits they’ve been asking for, and we’re not done yet. By delivering the industry’s highest ePMR capacities available today, we are ensuring that our customers have the storage efficiency, scalability, reliability, and unmatched value they need to stay ahead.”

Western Digital is using ePMR technology to make 26 TB Ultrastar DC H590 and Gold SATA drives with 11 platters, and 32 TB DC HC690 shingled drives, again with 11 platters. The areal density of WD’s 26 TB products is 2.36 TB/platter while its 32 TB disks achieve 2.91 TB/platter. This is less than the Seagate Exos 30’s 3 TB/platter and Exos 32’s 3.2 TB/platter; HAMR providing greater areal density than ePMR. 

Were Seagate to add an extra 11th platter, it could turn the Exos 30 into an Exos 32 and the existing Exos 32 into an Exos 35.2, using the same areal densities.

All three new Western Digital drives rotate at 7,200 rpm and have 6 Gps SATA  or 12 Gbps SAS interfaces, though the Gold Gold model has only the SATA interface.

Western Digital’s HC590 has an up to 288 MiB/s (302 MBps) sustained transfer rate, and the idle state power consumption is down to 5.6 W. The SMR HC690 has up to 257 MiB/s (269.5 MBps) sequential performance and draws down to 5.5 W when idle.

The HC590 follows on from the existing HC580 ten-platter drive with up to 24 TB capacity, while the HC690 succeeds the ten-platter HC680 28 TB shingled drive. 

Both the HC590 and HC690 are nearline drives for large-scale enterprise datacenters, cloud providers, and hyperscalers. The 26 TB Gold product is a nearline drive for system integrators.

The two new Ultrastar HDDs are being qualified and integrated into Western Digital’s Data60 and Data102 JBOD enclosures, with up to 60 or 102 HDDs respectively, meaning up to 3.26 PB of raw capacity.

A blog titled “Innovating to 11: Western Digital Increases HDD Capacity, Not Size” has background information on Western Digital’s 11-platter technology drives.