WD’s Energy Assisted Magnetic Recording HAMRs Seagate
As storage density on platter based hard drives increases, companies have had to find ways to be able to fit more data within a set physical area; you can only add so many platters before the drive won’t fit in 3.5″ bay after all. Shingled Magnetic Recording is one way this has been achieved but it comes with some drawbacks and so companies continue to work on new solutions.
Seagate is working on Heat Assisted Magnetic Recording, which uses a tiny laser to heat the platter to allow data to be written in a more precise manner than traditionally possible, without changing any data around it. Western Digital were working on a similar solution, Microwave Assisted Magnetic Recording, which used microwaves to write data in a smaller area. In both cases, this involves a lot of work, it doesn’t take much energy to reduce the coercivity of a specific place on a platter to allow you to make smaller writes without changing data located close to the targeted area which has slowed the release of these type of drives.
Ars Technica learned of a new solution coming out of Western Digital, and one which may allow them to provide product to consumers before HAMR can be finalized. Energy Assisted Magnetic Recording doesn’t change how the platters are written to, instead it changes how the write head works. By applying biased current to the main pole of the write head and the voice coils as well, they are able to successfully target smaller areas on the platter, without flipping any bits nearby and will be appearing in 18TB and 20TB EAMR drives in the near future.
Seagate's largest drives, like Western Digital's, needed a new technology to overcome the Magnetic Recording Trilemma—but Western Digital's EAMR (Energy Assisted Magnetic Recording) is considerably less-exotic than the HAMR (Heat Assisted Magnetic Recording) used by Seagate. That more conservative approach likely helped Western Digital beat its rival to market.