Memory and storage

Memory and storage

1. Primary storage

   • RAM
     • Faster to access than secondary storage
     • More expensive than secondary storage
     • Volatile
   • ROM
     • Often made from flash memory, so contents cannot be changed easily
     • Only stores small programs that boot up or start the computer (BIOS)
       • Basic Input Output System loads operating systems and checks system for errors
     • Fast
     • Expensive, so tends to be small
     • Non-volatile

2. Flash memory

   • SSD
     • Often used in home computers for performance
     • A form of re-writable flash storage
   • Secure Digital cards
     • Used to extend storage in cameras, smartphones or tablets
     • High capacity for physical size, useful in small devices
   • Not easily damaged by shocks (durable)
   • Appropriate for industrial machinery or vehicles to withstand lots of vibrations
   • Non-volatile
   • Can only be rewritten/flashed a certain number of times before it starts to degrade
     • May lose access after degrading to much
   • Rewritable devices often contain blocks of flash memory meaning only one block needs to be flashed at a time, making the device last longer
   • Faster than HDDs due to lack of moving parts