Storage Devices

Storage Devices

1. Hard Drives

   • Main storage device
   • Advantages
     • Large storage capacity
     • Cheap and Reliable
     • Quick at writing and reading data
   • Disadvantages
     • Can fail without warning
     • Slower then RAM

2. DVD

   • Capacity of 4.7Gb
   • Can be writable and rewritable
   • Blu-ray used for high-definition films and business backup as they have 50Gb
   • Advantages
     • Higher capacity than CDs
     • Only need one drive to read it
     • Fast data transfer
   • Disadvantages
     • Easily scratched
     • Many different types can be confusing

3. Magnetic Tape

   • Serial acces device
   • Archiving/Backing up
   • Advantages
     • Last 30-100years
     • 800Gb storage
     • Lost cost per Gb
   • Disadvantages
     • Only used for archiving/back up due to serial access
     • Being replaced by hard drives

4. Flash Memory

   • Capacity of 256Mb to 256GB, most are 1, 2 and 4Gb
   • Most common portable storage device
   • Advantages
     • Cheap, reliable and long lasting
     • Solid state
     • No special software needed
   • Disadvantages
     • Easily lost
     • Can be slow at transferring data
     • Limited capacity

5. CD

   • Capacity of 700Mb
   • CD-ROM is Read Only Memory
     • Already have data written on them, cannot be changed/deleted
       • Software and music
   • CD-R is Writable
     • Written to once, after that data cannot be changed but can be read
     • WORM disks-Write Once Read Many
   • CD-RW is Rewritable
     • Data can be changed many times
       • Back up medium
   • Advantages
     • Fast read speeds
     • Possible to store most software and music on one
   • Disadvantages
     • Slow write speeds
     • Scratched easily
     • Not enough storage for video