Western Digital is set to launch its highest capacity hard drive, offering 26 Terabytes of storage space.
To reach this milestone, the company relied on a technology called Shingled Magnetic Recording (SMR) – which overlays neighboring data tracks on the disk platter on top of each other, like roof shingles. This approach helps increase capacity at the expense of writing speed, making the new drives especially suitable for long-term storage in cloud environments.
WD is also launching a 22TB conventional server drive and a new family of high-capacity NVMe SSDs for cloud applications that leverage the higher bandwidth PCIe 4 interface.
The announcements were made this week at the What’s Next Western Digital conference in San Francisco.
"As a longstanding partner of the industry's leading cloud providers, we understand their unique requirements in building next-generation cloud infrastructure and invested in several HDD innovations we developed alongside our areal density technology," said Ashley Gorakhpurwalla, EVP and GM of HDD business unit at Western Digital.
"Our intent with taking this development strategy was not only to address the capacity demands of the world's largest cloud titans but to deliver on a roadmap that would also support the evolving economics of their data centers for decades to come.”
The largest drive you can buy
The 26TB Ultrastar DC HC670 features ten disk platters at 2.6TB each, achieving an industry-first in data density.
Like other high-capacity hard drives, it is filled with helium rather than air, since the inert gas offers less resistance. This simple property enables drive manufacturers to reduce power requirements, weight, disk vibration, mechanical wear, and internal temperature. WD started putting helium in some of its drives in 2013, while its main competitor Seagate joined the party in 2016.
Another trick used in the new drives is Western Digital’s energy-assisted perpendicular magnetic recording (ePMR) tech. This applies an electrical current to the element of the write head, enabling it to write individual bits of data closer together (technical explainer here). ePMR first appeared in commercial products in 2020, with Western Digital taking the lead.
And finally, the new drives leverage OptiNAND, a feature that replaces a small chunk of DRAM typically used in hard drives for a variety of caching operations with a larger chunk of flash memory that has the added benefit of keeping data intact in case of a power outage.
Looking to the future, WD said it was confident these technologies will enable it to produce hard drives with 30TB of capacity, and more. To ensure progress further along, the company continues to work on heat-assisted magnetic recording (HAMR) technology, which straps a tiny laser to the writing head in order to make the surface of the platter more receptive to magnetic effects.
Seagate appears to be further along with HAMR, launching the first commercial drives of this type in 2020.
Both the 22TB Ultrastar DC HC570 and the 26TB Ultrastar DC HC670 will begin shipping in the summer of 2022.