Why we can't combine GPU and CPU in the same processing unit?

CPU: Central Processing Unit

GPU: Graphics Processing Unit

    To understand why we (companies) cannot combine these two units into one unit, let us briefly explain the functions of both.

CPU:

The computer brain (heart, soul for some people). This is the most important part of a computer. It has three main parts.

• Control unit
• Arithmetic and logical unit 
• Memory unit

Control Unit:

Translates every instruction given to the computer into computer language and transmits it to other parts of the computer. Of course, it has control over every device connected to the computer.

Arithmetic and Logical Unit: 

This area processes the mathematical and logical instructions given to the computer. Its function is very important because a lot of information in a computer is in mathematical form. Here's how it goes.

Memory Unit:

The memory unit is the busiest computer that works from start to finish. Every action of a computer, whether it is related to control or mathematical or logical activity, is done from memory. What does a CPU look like?

This is an IC, an integrated circuit. Something similar to the normal circuit you have seen is made on a silicon chip. These circuits, which are small in size, are huge in number. It contains billions of transistors, capacitors. 

 Now let's see about 

GPU: 

 The GPU looks like this from the outside.

But in reality it is also an IC.

The graphics processing unit is typically used for graphics related activities. Although graphics tasks may seem easy to say, it is a very complicated process for a computer. For example: an Excel file with 100 rows and 5 columns is only about 20 KB (200,000 bytes) but a photo taken in your mobile is 2 to 3 MB (200,000 to 300,000 bytes). This means that a photo contains a lot more information than simple files.

It takes a lot of effort for a computer (CPU) to perform these images. So the CPU heats up and also slows down. Because you know that programming for a computer has many instructions. The instructions that the CPU can process are limited. If they are increased, the design of the CPU will become more difficult. GPU provides the same option. A GPU is designed to process difficult graphics instructions.

E.g. If the CPU takes 3 microseconds to process an image, then the GPU can do it in 1 microsecond or less. Complicated graphics tasks such as games, HD movies graphics cards (GPUs) are quicker and therefore reduce the stress on the CPU because the GPU is designed for the same task. Therefore, the CPU performs the rest of its tasks properly.

Now let us move towards to the main part of the question. 

Can we combine GPU and CPU in a single processing unit? 

So the answer would be yes. Manufacturers can combine GPUs and CPUs. Not only that, they can also do CPU + GPU + RAM + ROM but it has some advantages and some disadvantages as follows.

Advantages: 

 1. If the cost of the combined CPU is less than the total cost of different CPUs and GPUs then the computer will be cheaper. 

 2. Its speed will also be higher in comparison.

Disadvantages: 

1. When there is no need, you will have to take a package of CPU and GPU which will be more expensive than the available CPU. 

2. If the CPU goes bad, it will be more expensive than the CPU available now. 

3. It will be difficult to upgrade the computer. 

4. CPU and GPU options will be less available. 

5. The design of the CPU will be difficult and its size will be large. It can also get worse quickly as it gets too hot while the work is in progress.

There are also different companies that work on CPUs and GPUs. Graphics and CPUs can also affect sales if the customer wants different companies. Expect you better understand why they are not doing this.

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