Western Digital has produced prototype MAMR drives this year, and would give engineering samples to key customers in 2018 and start volume production in 2019. By 2025, further refinement of the technology would push capacities past 40TB. Currently the largest hard disk drive (HDD) that stores data on spinning disks can hold about 14TB of information. The bigger drives were made possible by finding a way to use microwaves to write data on 3.5in drives. The first bigger-capacity drives should go on sale in 2019.

Western Digital is able to demonstrate MAMR gains significantly above PMR by leveraging three breakthroughs: the design of a head structure in dimensions that allow for high track density, the selection of magnetic and non-magnetic materials that provide the right excitation and a manufacturing process that makes it feasible to mass produce at the required performance and reliability levels.