Western Digital considers HAMR time for really big disk drives

Microwaves or heat? Western Digital has yet to decide which is better for its future disk drives.

The company is adopting microwave-assisted magnetic recording (MAMR) technology but could still switch to heat-assisted magnetic recording technology (HAMR), as espoused by rival Seagate.

Western Digital will introduce MAMR technology with coming 18 and 20TB drives. Seagate is developing HAMR technology for similar capacity drives.

CFO Robert Eulau and Siva Sivaram, President, technology and strategy, told attendees at a Wells Fargo TMT Summit 2019 this month that HAMR technology adoption remains a possibility. WD expects rising production of 18TB and 20TB drives in 2020, especially for 18TB drives.

The company said it could adopt HAMR as capacities rise to 25TB and beyond. It remains agnostic about which technology will be its long term choice, out to 50TB disk capacities. WD has HAMR expertise, possessing more than 500 patents relating to HAMR tech, so could go either way.

Hard disk drive (HDD) capacities rise in two main ways. One is by adding platters to an enclosure – as with helium-filled nearline drives moving from 6 to 8 and 9 platters. The second is to reduce the size of the recorded bits and so cram more into a disk drive track.

Current perpendicular magnetic recording technology is producing 14 and 16TB drives but this is reaching its limit in terms of reducing bit size. The recording medium becomes increasingly unreliable and causes bit values to flip. Reformulated media requires energy to be beamed at a bit area before writing the data, which then becomes stable when the so-called energy assist  – microvaves or heat – is removed.