Western Digital showed off a a prototype hard drive with a potentially revolutionary new energy-assisted magnetic recording technology called microwave-assist magnetic recording (MAMR). The company says the new tech could potentially be ready for market by the end of 2019, and it could allow the manufacture of 40 TB hard drives by 2025. For context, WD is now currently offering 14 TB drives to datacenter customers and 12 TB drives are just entering the general market. The company performed the reveal at its "Innovating to Fuel the Next Decade of Big Data" event at its headquarters in Silicon Valley yesterday.
WD and its competitors have been working on drives using a similar energy-assisted recording concept called heat-assist magnetic recording for over a decade, with prototype drives demonstrated all the way back in 2007. MAMR has a research history that goes back just as far. Both technologies temporarily energize a small area of the magnetic surface during recording in order to increase recording density.
The company says a device called a device called a spin torque oscillator (or STO) is the core part responsible for making MAMR work. The basic obstacle to increasing areal density, as WD puts it, is that as magnetic media on disk gets smaller, heads also have to get smaller, and the challenge is generating enough magnetic field from the smaller head to actually modify the smaller media. The STO is vital to overcoming this issue, because the microwave field it generates permits modification of the underlying media with a lower-energy magnetic field that's easier to generate. Since MAMR doesn't have to heat the underlying medium, the payoff is increased recording density without sacrificing reliability, and it's all possible without employing new types of magnetic media, according to WD's technical brief.
The company says its Damascene head-making process is the second key component in bringing MAMR technology to a manufacturable state. The Damascene process involves precise depositing and etching layers of magnetic and non-magnetic materials to arrive at a finished head. WD says the resulting head has wrap-around shielding that helps focus the magnetic field and reduces interference with adjacent tracks. The manufacturing technique critically allows integration of the STO into the drive head, as well.
WD says that the material science and reliability challenges that have prolonged the development of HAMR are not an issue when it comes to MAMR. The company claims that MAMR can deliver on the reliability and cost targets needed by its datacenter customers, and HAMR cannot. HAMR drives rely on an expensive laser to increase the potential storage density of the magnetic media surface. WD also claims HAMR storage reliability is reduced when high heat is applied to a small, narrow area. Costs of HAMR-based drives are also driven up by a reliance on costlier glass platter substrates and iron-platinum magnetic coatings, instead of the cobalt-platinum media and aluminum substrates used in today's drives.
WD says the first drives with MAMR should be ready before the end of 2019. The company claims that MAMR, coupled with helium-sealed, shingled recording, and other technologies could allow the company to offer drives with a capacity of 40 TB in 2025 and even larger drives further into the future. More information about MAMR and some of the other technologies WD showcased at its event are available in this technology brief (PDF).