How Heat-Assisted Magnetic Recording works

We recently wrote about the need for storage media with greater storage capacities – focusing on Shingled Magnetic Recording (SMR) techniques and how this results in HDDs that are capable of storing more data within standard formats. Today, we discuss another means of achieving this: Heat-Assisted Magnetic Recording (HAMR).

Like Shingled Magnetic Recording, HAMR increases a hard drive’s storage density by increasing the amount of data each of its platters can hold. Whilst Shingled Magnetic Recording achieves this by allowing data tracks to overlap with one another, though, HAMR does it by decreasing the physical space needed to store each individual byte, thus increasing the amount of data the platter can store. Best of all, it does this by using lasers (we’re geeks at Fields Data Recovery and geeks love all things laser-related.

When the HAMR technique is utilised, a laser heats the surface of the drive’s platter whilst data is being written to it. This makes the material more receptive to magnetism meaning that less space is needed to store each byte. What’s particularly impressive is that the heating, cooling and writing process is completed is less than a nanosecond – and it was achieving this within such a small timeframe that was always the biggest problem engineers developing this writing technique faced. It was so significant a challenge, in fact, that a solution has been more than 50 years in the making.

HAMR isn’t exactly new

A patent outlining the basic process of using heat and magnetic fields in order to store data was filed in 1954. A now obsolete form of storage media known as the magneto-optical drive used a rudimentary form of HAMR in the 1980s. You may even remember Sony’s MiniDiscs; they were designed to replace cassette tapes and, just like the aforementioned magneto-optical drive, are now an obsolete piece of technology that made use of the HAMR writing technique. All in all, it wouldn’t have been a surprise if researchers had given up on it altogether. Indeed, at the time of writing, you cannot actually buy a HDD that uses HAMR technology for residential or commercial use – but that could soon change.

Reasons to be excited about HAMR

Seagate have, following more than a decade of research and development, begun manufacturing HAMR drives and began trialling them with selected companies in the latter half of 2017. The company have also stated that they have already built in excess of 40,000 HAMR drives as well as a significant number of HAMR read/write heads. Most importantly, they have also claimed that they will begin shipping HAMR drives with capacities of greater than 20TBs in 2019. 

The hard drive manufacturers have further estimated that they will be offering HAMR drives offering 40TB capacities in just five year’s time and that 100TB capacities will be available by 2030.

With the exception of DNA data storage – which still has a number of technical hurdles before it can be considered even a practicable cold storage solution – this represents that biggest potential improvement in storage densities currently in development. 

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