HAMR: Over 2 Tb/inchand Onwards

As discussed above, SMR and TDMR technologies combined are expected to increase the areal density of HDD platters by approximately 10% to 20% compared to platters used inside of today’s hard drives. Seagate has done a lot to make SMR viable for a variety of applications and we are yet to see the fruits of TDMR. However, keeping in mind physical limitations of PMR and SMR as well as high-cost of helium-filled HDD tech (as of today, according to Seagate), a new magnetic recording technology is needed. Yes, we are (finally!) talking about HAMR.

Seagate says that its HAMR heads heat media to approximately 450°C using a laser with 810nm wavelength and 20mW power. Seagate’s current internal HAMR-based HDD have an areal density of about 2 Tb/inch2, which is considerably higher when compared to today’s PMR or SMR HDDs. Potentially, this means that Seagate can increase the capacity of hard drives by 2x just by employing the technology. In reality, not everything is that easy.

The device, which heats storage media, is called a near-field optical transducer (NFT). Hard drive makers use gold as the primary NFT material due to its superior optical properties. On the other hand, gold has a comparatively low mechanical strength and such NFTs may experience reflow at elevated temperatures resulting in deformation of the NFT shape. A deformation in shape can reduce coupling efficiency and reduce the amount of light energy transferred to the storage medium, which essentially means a damaged hard drive. This is why Seagate and other makers of HDDs have researched and patented a variety of materials (alloys based on gold, to be precise) for NFT for years now. Seagate does not reveal the alloy it uses for NFTs for now.

Nonetheless, Seagate stresses that when it ships its first HAMR-based HDDs for evaluation (in 2017) and then for commercial systems (in 2018), they will be rated to work for a long time, just like today’s hard drives. Seagate does not reveal any data about its HAMR-based HDDs for now, but claims that they can offer several writes per drive per day over five years, which suggests pretty high reliability. Eventually, client drives will also rely on HAMR, but those HDDs are pretty far away from us at this point.

The HDD maker is not disclosing any details when it comes to transducer materials. Apart from a durable NFT, HAMR-based HDDs will need a new head (featuring a heater, a writer, and several readers to mitigate the ITI effect), which means a lot of work both on hardware on multiple fronts. In the end, HAMR-based hard drives will aim to add both capacity and performance. But to make everything work, Seagate will have to develop a rather robust platform, which will involve complex controllers in addition to new materials and a number of other things.

It should be noted that HAMR is a challenge for the whole industry, not just for Seagate. As a result, as soon as the industry figures out how to make HAMR-based hard drives as reliable as traditional HDDs, the technology will be used right across the board.

New 10K and 15K RPM HDDs Incoming Conclusion and Sources


View All Comments

  • Notmyusualid - Wednesday, July 6, 2016 - link

    Just lost my Seagate 4TB 2.5" internal disk last week.

    Luckily my most precious things were backed-up elsewhere, but dam, 2.4TB lost.
  • jwcalla - Thursday, July 7, 2016 - link

    I'm honestly fed up with the poor reliability of HDDs. Of the three ones I still had in service, two are dead, and I'll never buy those two brands again. Reply
  • Michael Bay - Thursday, July 7, 2016 - link

    Out of not so idle interest, what were they? Reply
  • kamm2 - Thursday, July 7, 2016 - link

    This was in the back of my mind the whole time I read this article. What good is any of this if the damn drives keep dying? Maybe things are different on the enterprise side but I've given up on Seagate drives. Reply
  • jbrizz - Wednesday, July 6, 2016 - link

    Can we just have 5.25 inch hard drives again? I don't care so much about density at home, but I need to hoard more files! Reply
  • rstuart - Wednesday, July 6, 2016 - link

    I like most have move to use SSD exclusively for the, hmm, "boot drive", But I do use HDD's for media storage where only the biggest highest density drive works. SSD's are currently about an order of magnitude more expensive per byte in this area. At a wild guess SSD's might reach price parity in a decade, but for now the HDD's are the only sane choice.

    I'm currently struggling to fit in 6TB. My guess is 10Tb would be enough for the foreseeable future, and 20Tb would cover everything I am every likely to need. So I rather pleased to see Mr Re say they will hit 20Tb in a few years.
  • patrickjp93 - Wednesday, July 6, 2016 - link

    Samsung is hitting 15TB this year, so Seagate is done in enterprise. The performance/watt/$ is just vastly superior for SSDs. Once storage density is also in the wheelhouse of SSDs, the scales will tip and never go back. Reply
  • gospadin - Thursday, July 7, 2016 - link

    absolute density (TB/m3) is already in SSD's advantage

    The biggest 2.5" HDD you can buy today is 2TB. In that form factor, Samsung is currently selling 4TB SSD, with 8TB/16TB drives announced.
  • Lolimaster - Friday, July 8, 2016 - link

    Do like me:

    4x6TB WD blues, so should be covers for some time.
  • anactoraaron - Thursday, July 7, 2016 - link

    This paragraph was enlightening -
    HDDs that use shingled recording write new tracks that overlap part of the previously written magnetic tracks. The overlapping tracks may slow down writing because the architecture requires HDDs to write the new data and then rewrite nearby tracks as well.

    Which explains why my 5tb seagate with this tech can't seem to get past 40MB/s when writing to the drive.

    Then read this - Ultimately, environments that involve a decent amount of writing might not be impressed with SMR performance, but the key figure here is density.

    Is anyone getting a high capacity drive going to be impressed with 2-40 MB/s?

    No. No they will not.

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