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)
