What is a CPU?

CPU is an abbreviation for Central Processing Unit. The CPU acts as the brain of a computer, where all information, operations, and data are meticulously calculated and commands are issued to control all the computer’s activities.

The Structure of a CPU

A CPU is composed of millions of transistors arranged together on a small circuit board.

A CPU is divided into 2 blocks and 3 parts: the control unit (CU) and the arithmetic unit (AUL).

• The control unit (CU – Control Unit): Here, the commands… Human requests and operations will be translated into machine language so that the CPU can understand, control, and process them accurately.

  Arithmetic Logic Unit (ALU): Mathematical and logical numbers will be carefully calculated and results will be provided for subsequent processing.

  Registers: These are small-capacity but high-speed memory units located directly within the CPU, used to temporarily store operands, calculation results, memory cell addresses, or control information. Each register has a specific function. The most important register is the program counter (PC), which points to the next instruction to be executed.

  Opcode: This part of memory contains the CPU’s machine code (optional) to execute instructions in the executable file.

  Control section: This section controls the blocks and the clock frequency. The system clock circuit is used to synchronize internal and external CPU operations at constant intervals. The waiting time between two clocks is called the clock cycle. The speed at which the system clock generates standard time signal pulses is called the clock speed – the clock speed in units of per second (MHz). This section is not necessary for a CPU but is mostly present in cisc architecture.

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  CPU Processing Speed

  Each CPU will have a different processing speed. The processing speed of a CPU is its computing and working frequency, measured in GHz or MHz.

  There are many technologies that increase the processing speed of the CPU, such as: Pipeline, turbo boost, hyperthreading…

  CPU speed also depends on many factors such as:

  • Number of processing cores (2, 4, 10, 22 cores…), the more cores, the more powerful

  • Manufacturing technology (32nm, 22nm, 14nm…), the smaller the technology, the more energy efficient and the higher the performance.

  • Technologies that increase the processing speed of the CPU (pipeline, turbo boost, hyperthreading) (threads…)

  • Cache memory – memory used to store frequently used instructions/data or those likely to be used in the near future, helping to reduce CPU waiting time.

  • Integrated graphics

  • TDP (Thermal Dissipation Power), the amount of heat the processor chip generates that the cooling system needs to dissipate. TDP usually indicates the power consumption of a chip; the lower the number, the better, helping to increase the lifespan and performance of the chip.

    If they are the same chip series, for example, a Core i3, the one with a higher clock speed means faster processing speed and better performance.

    However, if comparing two different chip series, such as a Core i3 with 2 cores and a 2.2GHz Intel Pentium with a 2.3GHz dual core, it’s impossible to immediately compare their speed and performance because the processing speed of a computer depends heavily on other components such as RAM, graphics chip, hard drive, etc.

    How CPUs Work What?

    There have been a number of improvements over the years since the first CPU appeared, but the basic function of a CPU remains the same, consisting of 3 steps:

    • Fetch:The fetch process involves the CPU receiving an instruction. The instruction is represented as a string of numbers and is passed to the CPU from RAM. Each instruction is only a small part of any operation, so the CPU needs to know which instruction will come next. The address of the instruction being transmitted is held by a Program Counter (PC). The PC and subsequent instructions are then placed into an Instruction Register (IR). The length of the PC is then incremented to reference the address of the next instruction.

      Decoding: When an instruction is fetched and stored in the IC, the CPU transmits the instruction to a circuit called the instruction decoder. Instructions are converted into signals that are passed through other parts of the CPU to perform the action.

    • • Execution:The decoded instructions are sent to the relevant parts of the CPU to be executed. The results are usually written to a CPU register, where they can be referenced by subsequent instructions. It’s similar to the function of memory in a computer.

      
      

      The Importance of a CPU

      A CPUis a central processing unit, essentially the brain of a computer. Without a CPU, a computer is completely incapable of functioning. It performs all the tasks we typically associate with computers. Most other computer components always support the CPU’s operation. Improvements made in processing technology, including hyperthreading and multi-core processing, played a crucial role in the technological revolution.