What Is a Processor Core


The processor core is the part of the CPU that does the actual processing. It’s the brain of your computer and is responsible for making everything happen. Originally, processors only had one core so there was no reason to differentiate between the t

Author: Trey Williams
Category: Hardware
Author: Trey Williams
Category: Hardware



What Is a Processor Core?

The Central Processing Unit (CPU) is considered the brain of a computer. The processor’s core is the part of the CPU that does the processing. In the days of early computing, a CPU would have been comprised of only one core so the words “processor” and “core” were used to mean the same thing. 

Most modern-day computers are now multi-core, meaning they still have one CPU but more than one core. Now, whether somebody is referring to the CPU or the core when they use the word “processor” will depend on the context.

The Central Processing Unit (CPU) is considered the brain of a computer. The processor’s core is the part of the CPU that does the processing. In the days of early computing, a CPU would have been comprised of only one core so the words “processor” and “core” were used to mean the same thing. 

Most modern-day computers are now multi-core, meaning they still have one CPU but more than one core. Now, whether somebody is referring to the CPU or the core when they use the word “processor” will depend on the context.

What Does the Core Do?

Computers use programs to make things happen. A program is just a huge instruction manual. Each step of the instructions is a process and a process is made up of smaller instructions called threads. The processor core completes individual tasks, or threads, in order to execute processes which result in actions you can see within the program or application you’re running.

A single processor core can only work on one single thread at any given time. It looks like it’s doing two things at once because it jumps very quickly between jobs on different threads within the same process while waiting for other things to finish, but it’s doing these tasks concurrently and not in parallel. As a result of this limitation, multi-core processors were designed so that the CPU could do more things at the same time. The majority of computers now utilize multi-core processors and an everyday model will typically include at least four cores.

What Are the Components of a Processor Core?

The processor core itself comprises three main component parts -  the Arithmetic Logic Unit (ALU), processor register and a control unit - all of which contribute different things towards the efficient functioning of the processor.

The ALU is responsible for calculating all arithmetic and logic operations. This might involve adding and subtracting numbers and deciding on logical outcomes by comparing different inputs. The register is a super-fast memory space which stores the memory address of the instructions, keeps the processor’s place in the list of instructions, and saves the outcome of the ALU’s operations. The Control Unit is responsible for decoding instructions and passing them on to the right place while also coordinating what the other parts of the processor are doing and keeping everything running smoothly.

How Does the Core Work?

Each individual task is completed by following an Instruction Cycle. Also known as the fetch-decode-execute cycle, the CPU follows this sequence every single time it receives an instruction.

The first step of the cycle - fetch - is exactly what it sounds like. To execute a program, its instructions are first copied into the computer’s main memory, usually RAM (Random Access  Memory). Each of the program’s instructions takes up an individual location in the memory and has an individual address. The core has to retrieve these instructions in order to be able to process them. A program counter within the CPU remembers all the memory addresses and is responsible for the instructions being processed in the right order. 

Once it’s been retrieved from the right memory address, the instruction needs to be decoded. The opcode (short for operation code) tells the processor what needs to be done, and on which operand. For example, in the instruction “slice the bread”, slice is the opcode and bread is the operand. The operand might also cover where the instruction should be carried out: “slice the bread on the plate”. The decoding of these instructions is carried out by the Control Unit.

Now it’s been decoded, the Control Unit knows where it needs to be sent for the execute stage of the cycle. Different instructions are executed (i.e. completed) by different parts of the processor. Depending on the instruction, this might mean going to the ALU for logic calculations, or to the processor registers to be stored for a future step. 

If the ALU is involved, the outcome of its calculation is saved in the main memory or sent on to external devices for use in other processes. This the final stage of the Instruction Cycle, known as write-back because it involves the writing of data into the computer memory.

The processor checks with its bookmark - the Program Counter - which instruction comes next and the whole cycle starts again. The fetch-decode-execute cycle will continue uninterrupted until the processor reaches a stop command in the program’s instruction set.

How Many Cores Do I Need?

While processor speed and number of cores are important factors to consider when buying or building a computer, your actual requirements will depend very much on what it is that you want to use the computer for. If it’s just basic usage - (internet browsing, word processing and spreadsheets with an occasional YouTube video), you can get away with a minimum of 4 cores. Whereas a professional working with 3D animation or giant, formula-heavy databases are going to need somewhere in the region of 24 to 32 cores.

What Is a Processor Core

Another thing to note is that brands like Intel often use the word core in their product names and model numbers, such as the Intel iCore 9. In almost all cases, the number of cores in the name does not equal the number of cores in the processor.

Summary

The processor core is the part of the CPU that does the actual processing. It’s the brain of your computer and is responsible for making everything happen. Originally, processors only had one core so there was no reason to differentiate between the two. Modern computers, on the other hand, will usually have one CPU which contains multiple cores. The number of cores you need will depend on what you want to do with your computer.

The core processing unit is made up of a Control Unit, ALU, and Processor registers, which work together, performing different functions in the execution of instructions. The core completes individual tasks that add up to execute processes and result in actions occurring within the program or application you’re running.

The core follows a sequence of steps - the Fetch-Decode-Execute cycle - in order to process every single instruction it receives. This begins the moment your computer boots up and continues until it receives an instruction telling it to stop.