April 28th Meeting: How Did Hard Disk Drive Track Widths Get That Small?

Time & Date:  6:30pm-9pm  April 28, 2015


Western Digital, 1710 Automation Parkway, San Jose, CA 95131
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Hard disk drives are all about higher storage capacity and that means higher areal density. Areal density is the product of linear density (density of bits along the tracks) and track density (density of tracks on the disk surface). In this IEEE SV History committee panel session we will examine how hard disk drive track widths have been reduced over over the last 50 years,  while continuing to be the storage behemoths that we still use today.

Over the 50 years of HDD history various ways have been used to try and reduce the track width of the recorded information.  These have included: improved servo technology, creating patterned tracks on the media surface, shingling recorded tracks and general improvements in head and media technology over time.  The panelists will be able to talk about all of these technologies and how they were trying to reduce HDD track width, increase the track density, and provide higher capacity mass storage products.


Moderator:  Tom Coughlin, Coughlin Associates (formerly with Seagate Technology, Maxtor, Micropolis, Ampex, Syquest and other companies)
  • Chris Bajorek, formerly at IBM and Komag
  • Dick Oswald, long time consultant
  • Ed Grochowski, formerly at IBM
  • Bruce Gurney, formerly at IBM and HGST

Timeline (this meeting only):

6:30pm  Networking Reception —   Donation Requested for food/drinks

7:00pm  Chair’s Opening Remarks

7:05pm  Introduction of the Topic by Tom Coughlin

7:15pm-8:30pm  Panel Discussion

8:30pm-8:50pm  Audience Q &A

8:50pm-8:55pm  Appreciation and Adjournment


One Response to “April 28th Meeting: How Did Hard Disk Drive Track Widths Get That Small?”

  1. Tom Gardner says:

    An interesting and informative panel, particularly on the subject of head transducer technology, but for the most part the panel seemed to avoid the subject of the session, “How did hard disk drive track widths get that small?”

    While S/N improvement driven by transducer, spacing and medium improvements are necessary for area density improvements, IMO they are not sufficient for the track reductions we have seen. After all wouldn’t an IBM 350 (RAMAC) with the best of today’s head and disk technology but at 20 tpi and a 10% track misregistration require a write head width of at least 10 mils to deal with the misregisration? That’s a long way from today’s about 200,000 tpi.

    It seems we need another panel to talk about which were the significant engineering activites that improved track misregistration by about 4 orders of magnitude over about 55 years. My guess at the top three: rotary actuators, fixed small disks and embedded servos.

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