It’s gotten more difficult for hard drive manufacturers to increase areal density in recent years, but manufacturers never stop pushing. Take Western Digital, for example. They’re currently working on 40TB drives.That’s more than three times the capacity of the largest drive the company offers today, and it wouldn’t even be possible without a major storage breakthrough called MAMR. It stands for microwave-assisted magnetic recording, and Western Digital says the technology will lead to drives with an areal density of a mind-blowing 4TB per square inch.MAMR itself isn’t a new discovery. Carnegie Mellon engineering professor Jimmy Zhu is credited with having invented the recording technology all the way back in 2007. Hey, it takes time to take things like this from the lab and slide deck to the factory.AdChoices广告This new generation of drives will utilize a “spin torque oscillator,” a tiny device that produces the microwave field. Western Digital says that it allows for read and write operations at the levels of speed and reliability required by data centers — which, like most new high-capacity storage devices — is where you’ll see MAMR drives deployed first.WD will also leverage many of its existing technologies in its new drives. Critically, they’ll continue the use of helium to reduce turbulence and drag as the platters spin.One other thing Western Digital wants you to know is that 40TB is just a starting point. They’re looking to push MAMR drives well beyond that mark as the technology matures. According to this week’s press release, they expect to bump capacities — and reduce cost — by around 15% every year.As for when you might be able to purchase one of these capacious new drives, that day isn’t as far off as you might think. WD plans to have the first MAMR drives up for sale in 2019.Let us know what you like about Geek by taking our survey.