CPU: what it is and how it works –

Have you ever wondered what’s at the center of your every action on any electronic device? We at BreakingTech are here to answer your question and to introduce you to the fantastic world of computers.

In this first part we will analyze the heart  of all devices, the central component of each computer; we are talking about the CPU .
Let’s not waste any more time and let’s analyze it in every part and we will do it in the simplest way possible, so that even beginners can understand.

What is a CPU

The name CPU  means  “Central Processing Unit” which, translated into Italian, means Central Processing Unit .
It is the component that executes the instructions of the various programs, and supervises the operation of the entire machine. It performs all the calculations, manages the transfer of data through the memories and disks and activates or deactivates the components of the machine.

As far as the computer department is concerned, there are only two big houses fighting each other to create the perfect processor, AMD and Intel .
Both, with their strengths and weaknesses, have been battling since 1975, when AMD launched the AMD C8080A CPU onto the market  . It was the low-cost rival of the Intel 8080 .

The processor is able to process the input data and provide an output response.
This process is divided into four phases, let’s discover them together.

The operation

To perform any operation on the computer, the CPU  performs four phases :


In the first stage, that of fetch , the CPU retrieves from the memory all the data necessary to perform the operation. They are then copied to the processor’s internal memory, the cache , so that you can access them faster when you need them.


The first phase follows a decoding process, better known as decode .  All data in memory are translated into binary language , so that they can be understood by the CPU . Before proceeding to the next step, the order of execution of the various operations is also established.


In the third phase, the CPU collects all the data and processes it with complex mathematical operations in order to return what we have asked for.


At the end of the execution phase, the result is copied into the memory and the next instruction is passed.

These are the four stages of the CPU explained in a simple way, but there is still a lot to know so let’s move on.

The fundamental components

The CPU is made up of several components but now we will deal only with the most important ones.

Arithmetic-logical unit

In our processor there is an arithmetic-logic unit called ALU ( Aritmetic Logic Unit ). It performs the fundamental arithmetic operations ( Executing ).

Control unit

The control unit called CU ( Control Unit ) takes care of establishing the logic with which the operations must be carried out by the ALU ( Decoding ).


There are also registers in the CPU , that is, memories that store data and instructions in progress.

Cache memory

Another very important element of the processor is cache memory . It is a very fast type of memory, which stores data and makes it immediately available to the processor as soon as it is requested.
In this way the CPU does not have to wait for the data to be sent from the RAM memory and the processing process becomes faster.

Processor speed

Processor speed depends primarily on the number of instruction cycles per second it can execute. The cycle we are talking about is the one listed above ( Fetching, Decoding, Executing, Write Back ).

The work rate of the processor is regulated by an electrical signal called a clock . It is generated internally by the computer and is made up of very rapid impulses that repeat countless times per second.

Clock speed is measured in GigaHertz (billions of pulses per second).
But not always the increase of the “beats” per second, corresponds to an increase in power.

In fact, going to perform the overclocking (increase of the clock with respect to the base speed) you will obtain a gradual increase in temperature which, if well controlled thanks to efficient heat sinks, will not cause us big problems.
But each medal has two sides, if we fail to control the temperatures there will be a decrease in performance or even  damage .

The processor can therefore be considered the heart of our machine and the clock is its beat. Therefore take great care of it, and at least once a year we advise you to change the thermal paste, in order to keep your “heart” always in the cold.


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