What is Core in a Processor? Function, Types & More

What is Core in a Processor?

The core refers to the processing unit within the processor or the CPU that can perform one task at a time such as reading instructions. A core consists of different parts of the CPU such as the registers, Floating Point Unit, Arithmetic Logic Unit, cache memory and Control Unit.


  • The cores of a processor play an important part in executing the commands received by it. Higher the number of cores, the better will be the performance.
  • Though the clock speed does not depend on the number of cores, the cores in a processor operate at their own clock speed.
  • Being just like a small processor, the cores perform the basic functions of a processor which is to fetch, decode, execute and write back.

A Brief Introduction of the Computer Program

A computer is a complicated machine which is easily programmable and a PC runs by performing various programs. A set of instructions is called a program of a desktop.

For a specific program, a PC performs a specific job. After getting any data from the user the computer processes the data in the CPU unit and it shows the result of it through output devices.

The central processing unit is the major executing unit in a computer. The main part of a PC is the CPU.

It is called the brain of a desktop. The CPU is also an assembled unit. It is made of several components.

  • Components of CPU

To understand what a core is, in a PC, it is important to know these components of the CPU because some of these components combine themselves to build up a core in a CPU.

  • ALU (Arithmetic Logic Unit)

ALU is the component of a CPU where various types of mathematical logical operations take place.

One can consider this unit as the ‘heart’ of the CPU where the thinking is produced.

  • FPU

The floating point unit is present in a CPU to support the arithmetic logic unit in handling large decimal numbers.

In performing various mathematical operations FPU is faster than ALU.

  • Registers

This is basically a memory. The CPU used to store the data of important instructions in the register memory while executing any operation.

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It also stores special status which is needed for faster execution of the operations in future.

  • Control Unit

Control unit is the headmaster of the CPU. It controls all the execution process, its steps, etc.

It works as a manager which actually controls and schedules the working process of the CPU.

  • Cache Memory

Updated modern processors also come with cache memory. After fetching the instructions from the RAM, this cache memory used to store the data.

This cache memory is the fastest memory, present inside the Central Processing Unit.

The stored data in this memory helps the CPU to execute the forthcoming operations, quickly and smoothly.

The FSB is the gateway which helps the data to travel in various parts of the system. It is the gateway which transfers the data from RAM to the CPU.

Understanding Core in a Processor

What is core in a processor

The core is one of the major parts of a computer. FPU, Register, ALU, Control Unit and Cache memory come together to form the core in a CPU.

Other components of the CPU are not a part of the core. The ‘Core’ was introduced after a long time from the invention of the CPU.

Day by day computers were getting smaller and faster. But, after a certain limit developers were facing problems, in creating more compact components.

In solving this problem the engineers started to attach multiple CPUs to make it more efficient and powerful.

In this process, the FSB plays a crucial role and the speed of the FSB was not able to fulfill the expectations of the engineers.

So, they dropped this method and started to develop a chip which is as powerful as a CPU.

But is this chip the heat-sink, mounting, power connection, and front-side-bus will be common for each core.

Thus the developers produced the multi-core processors. Each core is able to perform a single task at a time.

The Working Process of a Core in a CPU

Computers run various programs to run the operating systems and other applications.

The data is pre-stored in the RAM and the CPU or the processor executes the operation.

Then it sends back the result of it, to the RAM and then it is delivered to the users through various output devices.

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The process is performed in a specific order. Let us go through the executing circle.

  • Fetch

After getting any data from the users, the computer primarily stored it in the RAM. The Central Processing Unit used to fetch the data or instructions from the RAM.

  • Decode

The computer can only read binary language and it also operates on binary language.

But, the data we provide through the input devices are not in the binary core; rather they are in Assembly language which is not understandable to the CPU.

So, the PC needs to decode the inputted data in binary code.

  • Execute

After receiving the instructions in binary code, the CPU operates plenty of operations to reach the exact result of the data.

  • Write-back

After reaching the perfect result the CPU sends back the result to the CU. Then CU processed the result and provided the exact result to the users through output devices.

These four steps in exact sequence construct the Instruction Cycle. For every data or instructions of programs, the computer has to run this cycle plenty of times.

The fetch and execute cycle can be performed by each core, present in a PC. So, more cores make a PC stronger, as it can perform more numbers of Instruction Cycle.

  • The length of the instruction word

A set of binary bits is called the Instructions Word. A computer can process and execute a longer word quickly.

Throughout the years the length of the instruction was getting changed. Most of the processors of recent times come in 32 bits and 64 bits words.

For running any complex or classified software which needs to perform complex calculations, 64 bits processor is always preferred.

  • The clock-speed

The very advanced electrical gadget, the computer can only understand two digits 0 and 1 and it is through the very short electrical pulses.

These electrical pulses are called the clock-speed of a processor and it is measured in GHz and MHz. More electrical pulses make a PC faster.

We can say that the PC which is comparatively faster than another one has more clock speed.

  • The generated heat

If anyone thinks that he can infinitely increase the clock frequency, then he is wrong; because after a certain limit, the generated heat started to create a major issue.

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Each core of a processor runs on its own clock speed. Each core generates heat. That is why it is said that a good computer should be equipped with a good cooling system.

Types of Core

From its invention, the core in the CPU has gone through a continuous developing phase.

This is an era of Octa core processors. At the beginning of the century, there was an era of dual core processors; that means there were two cores.

Then Quad Core, Hexa Core, Octa Core were introduced. A Quad Core processor is equipped with 4 cores.

A Hexa Core processor has 6 cores and an Octa Core processor has 8 cores. The more cores make a system more efficient.

The user can choose the number of cores according to his requirements and budget. As the number of cores will increase, the price will be increased accordingly.

Importance of core

Core was introduced to make the CPU more compact and more powerful. Each core of a processor is an independent CPU.

The developers have compressed the CPU in a single core. So, the core is the heart of a processor and each core can perform only a single operation at a time.

To make a PC more efficient and more powerful the core plays a crucial role.


Although core was introduced later in comparison to that of the other components of CPU, it has now become one of the most inevitable parts of a CPU. Intel and AMD are the two trusted names in the field of processors.

Each of them has a wide range of products. Intel was the first company which introduced the multi-core processors. We can conclude that the core is the artificial brain of the CPU.

About Dominic Cooper

Dominic CooperDominic Cooper, a TTU graduate is a computer hardware expert. His only passion is to find out the nitty gritty of all computers. He loves to cook when he is not busy with writing, computer testing and research. He is not very fond of social media. Follow Him at Linkedin