Primary Storage

Primary Storage

1. RAM

   • Purpose
     • Short term memory
       • Main place for storing instructions and data whilst a program is being executed.
     • Part of Fetch, Decode, Execute cycle
     • RAM is much faster than a HDD or SSD
   • Volatile
   • Can be overwritten

2. ROM

   • Purpose
     • Gives computer instructions on how to start up
     • Loads operating system into RAM
     • Access built in hardware such as the HDD
   • Non Volatile
     • Does not lose information when power is turned off
   • Firmware
     • Cannot be overwritten

3. Differences

4. Cache

   • Purpose
     • Used to temporarily hold data and instructions that the processor is likely to reuse.
   • high-speed random access memory (RAM) which is built into the CPU
     • Faster than RAM because it is in the CPU

5. Virtual Memory

   • Purpose
     • When RAM is full, small area of secondary storage used as RAM to help