🔗 Heat-assisted magnetic recording

🔗 Computing

Heat-assisted magnetic recording (HAMR) is a magnetic storage technology for greatly increasing the amount of data that can be stored on a magnetic device such as a hard disk drive by temporarily heating the disk material during writing, which makes it much more receptive to magnetic effects and allows writing to much smaller regions (and much higher levels of data on a disk).

The technology was initially seen as extremely difficult to achieve, with doubts expressed about its feasibility in 2013. The regions being written must be heated in a tiny area - small enough that diffraction prevents the use of normal laser focused heating - and requires a heating, writing and cooling cycle of less than 1 nanosecond, while also controlling the effects of repeated spot-heating on the drive platters, the drive-to-head contact, and the adjacent magnetic data which must not be affected. These challenges required the development of nano-scale surface plasmons (surface guided laser) instead of direct laser-based heating, new types of glass platters and heat-control coatings that tolerate rapid spot-heating without affecting the contact with the recording head or nearby data, new methods to mount the heating laser onto the drive head, and a wide range of other technical, development and control issues that needed to be overcome.

In February 2019, Seagate Technology announced that HAMR would be launched commercially in 2019, having been extensively tested at partners during 2017 and 2018. The first drives will be 16 TB, with 20 TB expected in 2020, 24 TB drives in advanced development, and 40 TB drives by around 2023. Its planned successor, known as heated-dot magnetic recording (HDMR), or bit-pattern recording, is also under development, although not expected to be available until at least 2025 or later. HAMR drives have the same form factor (size and layout) as existing traditional hard drives, and do not require any change to the computer or other device in which they are installed; they can be used identically to existing hard drives. HAMR is expected to be delayed commercially until 2022, with 10-platter hard drives using perpendicular recording (expected to be followed by SMR) being used as a stopgap solution.