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Recent content by oberschelp

  1. oberschelp

    Spiral Layout for Hard Disk Drives

    Point by point: “If you had a spiral architecture, the calculations would be more complicated.” Yep. “To start with, how would you detect the sync point unless the disk had a special kink in it to tell the head where it was.” Did you see in the original post where I mentioned “a sensor to...
  2. oberschelp

    Spiral Layout for Hard Disk Drives

    OK. My takeaway (so far) is maybe HDD sectors could and should be organized in a spiral. Could – MikeHalloran sees possible problems, but is talking possible implementation methods. Should – I don't think anyone has shot a hole in the time savings, though IRstuff might still disagree.
  3. oberschelp

    Spiral Layout for Hard Disk Drives

    MikeHalloran, I followed paragraph 1 fine. I think I might have gotten lost in the 2nd, because it seemed to be talking about delays in all drive technologies. For example, I assumed ALL drives went open loop in the gross movement from initial track to destination track and closed loop aligning...
  4. oberschelp

    Spiral Layout for Hard Disk Drives

    IRstuff, I am not ignoring you. How is additional slowness produced seeking to a spiral sector vs a conventional sector? You move the head(s) to the sector. Period. What am I missing?
  5. oberschelp

    Spiral Layout for Hard Disk Drives

    Addressing the last three posts... IRstuff - “It takes 8ms to complete 1 track, so the incremental change is less than 12% improvement in performance.” True. We are talking about a maximum of 12.5% (or 16% at 10,000rpm) HDD read/write improvement. I'm calling that “significant”. MikeHalloran...
  6. oberschelp

    Spiral Layout for Hard Disk Drives

    And I didn't mean to give the impression the heads aren't moved by a voice coil. They are of course.
  7. oberschelp

    Spiral Layout for Hard Disk Drives

    Hi. Thanks for replying! "...what difference does it make ... given that an HDD is a random access device?" Because a large percentage of head movement requests are single track step. So, like I said, by eliminating these single track steps (track-to-track), it looks like HDD performance would...
  8. oberschelp

    Spiral Layout for Hard Disk Drives

    (Out of my field, so I apologize if I'm presenting this poorly, or if it is noobish.) Why are hard disk drives not made with user data and the servo information in a single spiral a la DVD? I ask because track-to-track seeking is so common, and reducing it from 1ms to 0 would be a big deal...

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