Secondary Storage

Secondary Storage

1. OPTICAL

   • data on an optically readable medium
   • Examples...
     • DVD
       • 4.7GB
     • CD
       • 25GB
     • Blu-Ray
       • 720MB
   • Characteristics...
     • Capacity - 4.7GB, 720MB, 25GB
     • Portable
     • Degrades over time
     • Speed - 50Mbps
       • Slowest

2. MAGNETIC

   • data storage using a magnetized medium
   • Characteristics...
     • Capacity - Up to 6TB
     • Speed - 3Gbps
     • Not portable
     • Can be damaged if dropped
     • Extremely reliable
     • 3TB/44p
   • Examples...
     • Magnetic Tape
     • Floppy Disk Drive
     • Hard Disk Drive

3. SOLID STATE

   • non-volatile computer storage that stores and retrieves digital information using only electronic circuits
   • Examples...
     • USB Memory Stick
     • SSD
   • Characteristics...
     • Capacity - Up to 240GB
     • Speed - 6Gbps
       • Fastest
     • Portable
     • Very durable
     • Expensive
       • 128GB/£40