Secondary storage

Secondary storage

1. Magnetic strorage

   • uses moving read/write electromagnets
     • creates magnet charge which creates either 1 (on) or 0 (off)
   • large capacity, faster than optical drive
   • cheap/easy to replace data not lost
   • parts eventually fail
   • easily damaged, noisy and large power consumption

2. Optical storage

   • reflects light to read data uses pits to represents 0s and lands represent 1s
   • easy to store/carry
   • long lasting and easy to use
   • data is permanent
   • require special drives expensive easy to break

3. SSD

   • record data with transistors
     • work without power
     • faster than normal drives
     • non-volatile
     • lightweight, durable silent less power
     • limited storage capacity
     • random write speeds 4x slower than magnetic drives
     • more expensive, only erase and write data 100,000 times

4. Flash memory card

   • An SSD using flash memory
     • used with cameras, phones mp3 players (small devices)
     • Small portable, light, durable
     • don't need internal power, use less power than magnetic drives, silent
     • hard to read across multiple devices, easily corrupted/broken/lost
     • more expensive