Unit 1.2 CPU and System Memory

Unit 1.2 CPU and System Memory

1. RAM

   • Random access memory holds information as long as the computer is switched on and the data is erased when the computer is switched off.
     • This is volatile storage.
   • DRAM
     • Dynamic Random Access Memory requires constant power to store data.
   • SRAM
     • Static Random Access Memory doesn't need power to hold onto data.

2. ROM

   • Read Only Memory stores information even after the computer has been turned off and tends to be used for data such as instructions to start a computer system.
     • This non-volatile storage.
       • Flash Memory is another type of non-volatile storage. This is a storage medium that can be erased and reprogrammed.

3. The hard drive is responsible for everything to do with storage and memory on the computer.

4. Firmware

   • A type of program that provides low level control over the device's specific hardware.
     • BIOS is non-volatile firmware that performs hardware initialisation during boot up process.

5. CPU

   • The Central Processing Unit carries out instructions necessary for the computer to run.
     • Factors that affect performance...
       • CPU Components
       • Cores
         • Eg. Dual cores, Quad cores, 8 cores
         • Each core executes information individually
       • Cache Size
         • Holds frequently used instructions
           • Holds data and makes the CPU faster. The bigger the cache size the faster the CPU.
             • Very fast but a small amount of memory.
       • Clock Speed
         • This indicates how fast the CPU can run and how many instruction cycles it can go through per second.
           • Measured in mHz or gHz
       • Processor Type