What Is a CPU & What Does It Do?

What is CPU? The CPU or Central Processing Unit is the computing brain of a computer. Everything a computer does, from video games to essay writing assistance, is broken down into a set of mathematical instructions. The CPU takes these instructions and executes them.

The details of how he does this are of course much more complex than this simple explanation. The most important thing you need to know is that the CPU is the main mathematical engine of the computer.

A (very) short history of CPUs

The history of computing is long and complex. It also goes deeper than digital technology, electronics, or even electricity. Abacus is a kind of processor. So are mechanical calculators. The big difference is that these machines can only do one or a few math problems. These are not general-purpose processors like modern CPUs are.

What makes the CPU a general-purpose computing device is the use of logic. In 1903, Nikola Tesla patented electrical circuits known as gates and switches. Using these circuits, you can create devices that perform logical operations where you can force a machine to act under certain conditions.

In the mid to late 1940s, William Shockley, John Bardeen, and Walter Brattain invented and patented a device called a transistor while working at Bell Laboratories. The transistor is the main building block of the CPU. Transistors are relatively tiny computer components. The transistor is such an important invention that three inventors were awarded the Nobel Prize for it.

In the late 1950s, Robert Noyce and Jack Kilby took a huge step forward and created the first working integrated circuit. An integrated circuit is a collection of electronic circuits combined into a single piece of semiconductor material. In most cases, this material is silicon. This is what people mean when they say microchip.

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A CPU is made up of one or more microchips. This is an important invention because billions of transistors can be housed in a single processor. This creates incredibly powerful mathematical mechanisms.

Thanks to the inventions of logic gates, transistors, and integrated circuits, the whole world has changed. These days, microchips are in everything, not just your computer. And processors are the most advanced general purpose ICs we can make.

How do CPUs work?

The whole CPU principle is binary based. People tend to represent numbers in a system called base 10 , or decimal. The digit values ??of each digit of the number are increased tenfold. So “111” contains one hundred, ten and one.

Computers and their processors do not understand radix 10 at all. Transistors operate on an on or off basis. This means that the logic gates you build from them can also only work with these two states. This is why, in essence, processors run in binary . This number system uses different bit values. Instead, if 1, 10, 100, 1000, and so on, the digit values ??would be 1,2,4,8,16,32,64,128 and so on.

So, in binary, “111” would be 7 in decimal numbers because you are adding 1,2 and 4 together. If any of the numbers are zero, you just skip it and add the digit value of the next 1. That way you can express any decimal value. Just note that binary numbers are often read from right to left, so the value “1” will be on the far right.

Let’s put it in a table to make it clear:

Do you understand why the sum adds up to the decimal number 7? Let’s make the number 23:

So 111 is 7 and 11101 is 23 because fifth in binary is 16. Pretty cool, right? In this way, you can express any possible number that can be written in decimal system. This means that computers built on transistors can also work with any numbers.

How are CPUs made?

The manufacturing process for modern processors is, as you might expect, rather complicated. The main process involves growing large cylinders from a silicon crystal. Its semiconducting properties make it ideal for building binary integrated circuits.

These large crystals are cut into thin slices. The plates are then “doped” with another chemical to fine tune its properties. The nanoscale diagram is then etched onto the surface of the wafer using light through a process known as photolithography

CPU design and performance

Not all processors are created equal. The first true ancestor of modern CPUs, the Intel 8086, had about 29,000 transistors in its integrated circuit. Today, a processor like the Intel i99900K has just over 1.7 billion transistors. The denser the logic of the CPU, the more complex and more instructions it can execute per clock.

Wait, “clock cycle”? Yes, this is another important component of processor performance. The CPU runs at a specific frequency, with each CPU clock pulse, a computation cycle is performed. If you take the same processor and double its clock speed, then (in theory) it should run twice as fast.

That 1978 Intel 8086 ran at 5 MHz when it was released. This is five million ticks per second. Intel i9-9900K? It starts at 3.6 GHz, which is 3600 MHz, with the option of increasing to 5000 MHz when possible.

To add another downside to CPU performance, modern CPUs actually contain multiple “cores”. Each core is actually an independent processor. It is typical these days to have at least four of these cores, but recently, the norm for conventional computers has been six or eight cores. High-end professional computers can have around 100 CPU cores.

Multiple cores means the CPU can execute multiple sets of instructions in parallel. This means that our computers can perform many tasks simultaneously without any problems. Some processors have “multi-threaded” cores. Each of these cores can perform two separate tasks. Intel processors call this “hyper-threading”.

Thus, the overall performance of a CPU depends on the following factors:

• The total number of transistors and the degree of sophistication of its logic circuits.
• Clock speed
• Cores
• Threads

Of course, there is more to it than these four main points. However, these are four main factors for which a CPU should perform well.

The role of the CPU in your computer

The last thing we have to consider is what kind of work the CPU is doing on your computer. After all, this is not the only microchip on an integrated circuit in your computer. For example, GPUs (GPUs) are often even more loaded with transistors than CPUs.

They need their own cooling and power supply, as well as memory. It’s like a little extra computer! The same can be said for the chips that control your sound, USB, and hard drive traffic. So why is the processor special? These are the main reasons:

• It can process ANY instruction, the GPU does only certain types of processing.
• It ties all the other components together, sending and fetching data to make your computer run
• The CPU is more or less involved in all the work that the computer has to do

In short, the CPU is the most important component of the performance of your general purpose computer. Don’t take it for granted!

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