Western Digital Shares Roadmap: 26TB Today, 50TB Tomorrow

Western Digital this week introduced its all-new 22TB and 26TB capacity hard drives, which use conventional magnetic recording (CMR) and the so-called Ultra SMR technology, respectively, and shared details about its future roadmap at its Investor Day event.

The company said that its 2nd Generation energy-assisted perpendicular magnetic recording (ePMR 2) technology will enable it to build 32TB + HDDs in the next few years, but that heat-assisted magnetic recording (HAMR) will be required to hit capacities of 40TB to 50TB. Interestingly, Western Digital also talked about 50TB products for archival applications that are ‘just around the corner.’

ePMR 2: 24TB ~ 30TB + HDDs

Several years ago Western Digital said it would use microwave-assisted magnetic recording (MAMR) technology to enable the next generations of its hard drives, but eventually it discovered that a much simpler ePMR technology could do the job, which is why MAMR sidelined. Over time Western Digital has ceased mentioning MAMR publicly and has now removed any mention of MAMR from its plans.

(Image credit: Western Digital)

Western Digital says ePMR 2 will power its hard drives with capacities from 24TB to 32TB and higher in the coming years. Slides from Western Digital’s presentations at its Investors Day conference do not directly mention availability timeframes for 30TB + ePMR 2-based HDDs. To get to higher capacities Western Digital will need HAMR technology, which is set to arrive in 2026 for Western Digital, so we can speculate that 30TB + ePMR 2 hard drives will become available before that.

(Image credit: Western Digital)

It is necessary to note that while technologies like ePMR 2 and HAMR will increase areal recording density for HDDs, there will also be other ways for Western Digital to increase hard drive capacities. Shingled magnetic recording (SMR) in its regular or ‘UltraSMR’ form increases capacity by 10% to 20%, but there are more ways to boost capacity of an HDD.

(Image credit: Western Digital)

Across the Board Innovations

To build higher-capacity HDDs, Western Digital not only has to adopt new magnetic recording methods, it also has to implement a host of technologies. The company’s 3.5-inch 22TB Ultrastar DC HC570 HDD is based on an all-new 7200 RPM-class helium-sealed platform that integrates 10 ultra-thin AlMg platters, each with a 2.2TB capacity, as well as ePMR write heads that change coercivity of magnetic media with energy assistance, plus two-dimensional magnetic recording (TDMR) read heads that can reliably read data from very thin tracks. By contrast, Western Digital’s 20TB CMR HDD uses nine platters. The company’s latest drives also use triple stage actuation and Western Digital OptiNAND technology to further increase usable capacity (by storing service data on NAND flash).

(Image credit: Western Digital)

Western Digital’s 22TB HDD uses conventional magnetic recording technology and looks to be drop-in compatible with existing infrastructure, and will be available to operators of exascale datacenters, server makers, and channel resellers this summer. Eventually the manufacturer plans to ship 22TB WD Purple Pro, WD Red Pro, and WD Gold HDDs.

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