Secondary Storage

Secondary Storage

1. Magnetic Storage

   • Magnetic Tape
     • <185 TB
   • Hard disk (HDD)
     • <8 TB
   • Floppy disk
     • <1.44 MB
   • Tape/Disk based
   • Magnetic dots of data
     • Binary

2. Optical Storage

   • CDs
     • <700 MB
   • DVDs
     • <9.4 GB
       • Single layer: 4.7 GB Dual layer: 9.4 GB
   • Blu-ray disks
     • <128 GB
       • Single layer: 25 GB Dual layer: 50 GB Triple layer: 100 GB Quadruple layer: 128 GB
   • Laser reflected light
     • Binary
   • Land and pits

3. Solid State Storage

   • Solid State Drives
     • <4 TB
   • SD Cards
     • <2 TB
   • USB drives
     • <1 TB
   • Flash Memory
   • Non-mechanical
     • Electrical Circuits

4. Properties

   • Non-volatile
   • Higher capacity than primary storage
   • Indirectly accessible through RAM
   • Slower than primary storage
   • Some devices are removable