Role of processor in a PC

The processor also known as CPU is a piece of hardware. It is often referred to as the “Brain of a PC” because all the computations and processing are carried out directly or indirectly by the processor containing millions of transistors. It is a single chip that is capable of processing data. In fact, the performance, capability, and pricing of a computer system are largely determined by the processor to present in it. It controls all the components in a PC. The primary functions of a processor are -

1. Fetch - 
   Every instruction has its own address and is stored in the main memory. The CPU fetches the address of the instruction which is to be executed from the program counter in the memory and performs the instruction.
    
2. Decode - 
   The instruction that is to be executed is converted into binary code so that the computer can easily understand it and perform the required function. The process of conversion is known as decoding.
    
3. Execute - 
   The process of performing the required task specified in the instruction is known as execution The execution of the instruction takes place in the CPU.
    
4. Write back - 
   After performing the instruction the CPU store the result in the memory that process is known as a store or Write back.

Below is the diagram of the Processor

The processor plays a significant role in the following important aspects of a computer system.

• Performance - 
  The processor is probably the most single determinant of system performance in the PC. While other components such as memory, hard disks, display adapters, etc. play key roles in determining performance, the processor's capabilities have the greatest impact on the performance of a system. The core and clock speed of a processor determines the speed of a PC. They tell us how much information can be processed in how much time. In fact, the other devices present in the system play their roles to allow the processor to reach its full potential.
   
• Software support - 
  Newer, the faster processor enables the use of the latest software, which provides support for running heavy software on our PC and saves our time by working efficiently and with faster processing. 
   
• Reliability and Stability - 
  The quality of the processor is one factor that determines how reliably the system will run .while most processors are dependable some processors or not. This also depends to some extent on the age of the processor, energy consumption of the processor, motherboard, power supply voltages, cooling, etc.
   
• Energy consumption and cooling - 
  Originally processors consumed relatively little power compared to other system devices. But some processors consume a great deal of power. Power consumption has an impact on everything from cooling device selection to overall system reliability.
   
• Motherboard Support - 
  The processor is the system is a major determining factor in the selection of chipset and the type of motherboard. The motherboard in turns dictates many facets of the system's capabilities and performance.