Computer Science Revision

Computer Science Revision

1. Clock Speed

   • Usually measured in MHZ ( Megahertz ) or GHZ ( Gigahertz )
   • Refers to the speed of which the processor executes instructions
   • The main cycle Fetch, Decode and Execute
   • The faster the clock speed the more instructions the processor can complete per second

2. Secondary Storage

   • Storage that separates from the computer itself ( Like a Hard drive/USB stick )
   • Soft ware and data can be stored on a permanent basis
   • Necessary for memory as primary loses it's data when the computer is switched off
   • Commonly referred to as non-volatile storage

3. Number of cores

   • Processors can have a single core or multiple cores
   • it is common in computers to have two dual cores and four quad cores
   • A core contains an ALU ( Arithmetic Logic Unit ) and a control unit as well as a register