CACHE MEMORY

CACHE MEMORY

1. MOST DATA IS STORED ON THE HARD DISK

   • WHEN THIS DATA IS USED IT IS LOADED INTO RAM
     • THIS IS MUCH FASTER TO ACCESS THAN THAT FROM THE HARD DISK
   • IT IS VOLATILE

2. CPU NEEDS TO ACCESS DATA VERY QUICKLY

   • ALTHOUGH RAM IS FAST NOT FAST ENOUGH FOR THE CPU

3. SPECIAL TYPE OF COMPUTER MEMORY

   • ACCESSED MUCH FASTER THE RAM

4. CPU LOOKS IN CACHE FOR DATA IT NEEDS

   • IF DATA IS THERE IT WILL RETRIEVE IT
   • IF THE DATA IS NOT THERE THE CPU WILL ACCESS THE SYSTEM MEMORY AND THEN PUT A COPY OF IT INTO CACHE

5. INTERNET ADDRESSES ACCESSED FREQUENTLY BY PUPILS AT A SCHOOL WOULD BE STORED TO IN CACHE MEMORY

   • WHEN A PUPIL REQUESTS A WEBSITE THE PROCESSOR WILL CHECK FOR THE WEB ADDRESS FIRST OF ALL
     • IF THE WEB ADDRESS HAS BEEN ACCESSED BEFORE THEN THE ADDRESS WILL BE STORED HERE ALLOWING AN INCREASE IN RESPONSE TIME