A quick summary of week 11 which was a brief and perhaps dated review of storage devices:

  • Magnetic Disks
    • Direct Access Storage Devices (ie Hard disks/Floppy Disks) –  Organized by sectors, tracks and cylinder heads
  • Total (Disk) Access time – Total time it takes to read a piece of data – seek time + rotational delay + Data transfer time
    • Seek Time – time to position head over required cylinder (usually 4-8ms)
    • Rotational delay – time for desired sector to pass under the head (avg. 4ms)
    • Data Transfer time – >1ms
  • Magnetic Tape – Cheap sequential storage medium (only used for logging these days)
  • Optical Storage – CD-ROM/DVD/HD-DVD/BlueRay
  • Solid State –  USB Keys/SolidState Hard-drives (more information: http://en.wikipedia.org/wiki/Solid-state_drive)
Intel's SSD range (quickly coming down to a reasonable price)