Computer hardware

Computer hardware

1. Computer architecture

   • the internal logical structure and organisation of a computer hardware

2. binary

   • a system of two digit, 1 and 0 also knows as base 2 system

3. CPU

   • Central processing unit containing the control unit, ALU and cache memory
   • control unit works with the CPU to control the flow of data
   • ALU perform arithmetic and logical operations
   • in order to process information the CPU needs to access the RAM and cache memory
   • processing of a computer program
   • what does it do?
     • fetch collect data from RAM or Cache memory
       • decode makes sense of the information collected
         • execute process the data
   • cannot access data directly from the hard disk because it takes too long and therefore the data needs to be stored on to the IAS's memory and the CPU fetched the data that it needs

4. The Cache and RAM are primary storage as it is used when the computer is turned on and stores the programmes that are being used by the user

5. the hard drive and other external storages are secondar storage because they store data that needs to be kept even when the computer is turned off. they are non -volatile storage.

6. Immediate access storage- Cache- backing storage is too clow to access to be able to run applications directly.

7. Dual core or quad core device is two or four CPUs places in computer so more operations can take place at one time. the information is shared between the cores therefore the performance would increase

   • does not double processing power because some applications are not written to take advantage of extra processors.

8. RAM is not fast enough to cope with the speed that the CPU needs o deal with therefore it needs another storage. this means you need to store as much data as possible as close to the CPU as possible and the storage is the cache

9. Clock speed

   • a computer can only process one instruction at once however it is processing so fast that everything seems to be happening at once
   • measured in Hz
   • average 3GHz/s(3 million times per second
   • higher clock speed means that more processing will take place
   • over clocking- forcing a computer to operate faster that the manufactured speed. voltage may increase which can increase the speed at which the oeration remain stable
     • CPU run hotter and cooling fan have to be purchased
   • but this can not always happen as the main memory cannot work at the same speed as the CPU therefore the instructions are copied onto the cache which performs at a similar speed to the CPU

10. Performance

    • more cache on a device usually means better processing speed however the are expensive

11. the speed is also limited by the speed data and control signals. they move around the system on buses

    • the bus is a circuit that connects part of the motherboard.
      • the speed of the bus is the amount of data that can move around the bus at the same time.