A 160 TB disk drive?

A 160 TB disk drive?

Summary: About every 10 years hard drive technology bumps into the laws of physics. And for the last 50 years scientists and engineers have figured out ways around it. 3-D recording may be the next bit of magic.

TOPICS: Storage, Hardware
160 TB disk drive

Hard drives are beginning to reach the limit of current recording technology – about one terabyte per square inch. With present technology higher densities are risky because at such tiny sizes thermal fluctuations can cause bits to flip on the hard drive surface.

Regular readers of Storage Bits know that there are two promising technologies to overcome the current limitation: Heat Assisted Magnetic Recording (HAMR) and Bit Patterned Media (BPM). Magnetic bits written at higher temperatures are more stable when they cool and bit patterned media enables higher densities by enabling the use of the entire volume of the magnetic pit.

But even these heroic and not yet proven feasible for mass production technologies will only take hard drives up to about 20 TB capacity. That's where 3-D magnetic recording could save the day.

In a recent paper, authors Nissim Amos, John Butler, Beomseop Lee, Meir H. Shachar, Bing Hu, Yuan Tian, Davil Garcia, Rabee M. Ikkawi, Robert C. Haddon of the University of California Riverside, Dmitri Litvinov of the University of Houston, Jeongmin Hong and Sakhrat Khizroev of Florida International University document their success in creating an 8 3 bit 3-D magnetic cell.

With a three layer magnetic medium and some esoteric magnetic techniques - Kerr rotation - they successfully wrote and read 8 different magnetic states in a single BPM cell. The cell's three layers are different thicknesses to overcome the problem of distance from the read/write head.

Screen Shot 2013-10-14 at 8.42.34 AM
(Image: courtesy of the authors)

The Storage Bits take

A laboratory demonstration does not a commercially viable product make. However the fact of 3-D recording breaks a basic limitation of 2-D recording that the industry has been living with for decades. Nor is this the only exploration of 3-D recording techniques today.

What this does show is that simplistic extrapolations of semiconductor improvements - as wrongly applied to NAND flash – versus magnetic recording bit costs demonstrate nothing about the future of hard drive success.

With sufficient investment and continued refinement of the underlying technologies it should be possible to build 160 TB hard drives within 10 years. At that point, tape will be well and truly dead, as hard drives replace it.

Comments welcome, as always. When is a hard drive too big? Some thought 9 GB was too big.

Topics: Storage, Hardware

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  • don't drop it

    that sounds like a big investment to make
  • Minor correction

    AFAICT it's not eight bits but three bits yielding eight signal levels. Still, an interesting development.
    • Good catch!

      Thanks! I'll update.

      R Harris
  • Is tape alive today??

    "At that point, tape will be well and truly dead, as hard drives replace it."

    It astonishes me that anyone uses tape today.

    Tape is flimsy, exposed to dirt and dust, a slow serial medium and only available in relatively low capacity units.

    Disc is rigid, free from dirt and dust, a fast random access medium and available in large capacity units (4 terabytes on a single hard drive when I last checked).

    Add to the above comparison the fact that if a disc drive fails, you've only lost what's on that one disc. If a tape drive fails, you can't access the data on ANY of the backup tapes!
    I speak from experience as when our tape drive died, I found it was obsolete so we couldn't buy a new replacement. Moreover, every time you back up to tape, you're using the same tape drive. Every time you back up to disc, you're using a different disc drive so a disc drive inherently has less wear than a tape drive.

    I'd love to hear a single valid argument in favour of tape even at today's hard disc capacities - and don't quote cost as the cost of a failed backup can be astronomical.
  • Why would this kill tape?

    Why would the same technique not be applicable to tape, yielding comparable data density increases? Why must every technical advance be couched in terms of competing with related technologies?
    • Why Would this kill Tape?

      I thought tape had died a decade or 2 ago. have not trusted it or used it since.

    • tape cannot maintain the

      strict location for the read/write head to track if the track size and density were that small.. pulse being a two coating product, that many layers would make the tape a lot thicker and less pliable.. or you would be breaking off the coatings to lose data that way. Tape is typically a magnetic medium on one side and a friction material on the other side so the traction wheels can pull the tape at a consistent speed across the head. the jump from the 160 MB To 2 Gigabyte was a change in the magnetic coating.. and then the change from a fixed head to a helical scan allowed them to write 2 to 8 times the data to the tapes.. without a major change to the magnetic layer chemical makeup.. but a hard drive depends on a fixed location for the tracks.. they can be more narrow because they do not move side to side as tape can.. they are stiff so the thickness is adjusted for when the heads are aligned to the drive. you cannot have tht when the heads are fixed, mostly, and the media is floppy and moves al over the place..
      That is why tape is already a relegated to lesser position is most enterprises.. we just copy the drives from one site to another to back it up.. and multiple copies at each site for the more critical data.. tape just cannot handle the speed to back up several terabytes.
  • Let's hope...

    ... the bandwidth of the bus in desktops increases with the storage capacity of these drives. Otherwise, we're going to be back to the days of drive backups taking days to complete. At 160 TB, I might even be able to fit my entire audio and video collections on a single drive. That would be a wonderful day, indeed.
  • Good luck with backups of that large a drive!

    Backups to the cloud would take forever to upload, and local backups would require another 160 TB drive!
    • Terabyte removable media backups required

      Exactly! And we don't have to wait 10 years to have a problem. We have one now. There is no good backup solution for even today's today's 4 TB drives, let alone higher capacity HDDs.

      At 50 GB each, it takes approximately 80 regular double sided BluRay discs to back up a single 4 TB HDD. Using 100 GB BDXL discs would cut that in half but is still not practical. The cost of the media alone greatly exceeds the cost of the HDD itself. Neither is a second 4 TB drive practical as they are fragile and much larger.

      More than larger HDDs, we need inexpensive terabyte capacity removable media backup solutions.
  • Storage

    Well that puts my delay line storage in the bin :D