CPU vs GPU | Difference between CPU and GPU

You must have heard about the CPU a lot of times of how it is the main functioning body of the computer. The CPU is an integral part of the computer. It can be referred to as commander in chief for all the tasks performed by the computer.

Similar to this are GPUs. You might notice that some games can run smoothly on some devices while not as much on others.

This difference comes from the absence and type of GPUs. Let us dive deeper and understand the differences between CPU and GPU.


CPU

The CPU is the brain of the computer. The CPU follows the steps, fetch-decode-execute repeatedly to process multiple tasks assigned to the computer. It comprises two blocks- ALU and CU. The ALU (arithmetic logic operations) handles all the calculation and logic-based tasks of the CPU.

While the CU(Control Unit) is responsible for controlling the processes and scheduling them. The control unit releases control signals that help in performing tasks sequentially.

The CPU not only handles the assigned tasks but communicates with other units like the output unit, an input unit, memory unit, etc. of the computer as well.

Now the basic architecture of the CPU consists of several cores(ALUs), control unit, DRAM, and Cache.


GPU

The GPU or the graphics processing unit is specially designed to tackle parallel processing in high graphic games and for video rendering. Unlike its close cousin-CPU, the GPU has is built only for enhancing the image and video quality of games.

GPU



It has got nothing to do with interaction with other units of the computer. The GPUs also come in two different types- integrated and discrete. The integrated GPU comes embedded in the device alongside the CPU.

While the discrete GPU is integrated on a distinct chip, mounted on its circuit board, and is attached to the PCI express slot.

Now that we know what do the terms CPU and GPU mean let’s have a look at how they are different from each other.


GPU vs CPU – Difference between CPU and GPU

CPUGPU
A CPU can handle multiple types of data. For example, you can work on MS Excel, Powerpoint, listen to music, etc. at the same time.A GPU can handle one data type at a time. For example, if you are playing a game, then one part of the GPU will handle the anti-aliasing of the background and the other part will trace the user’s movement, etc. Therefore, GPU can process just one data/application.
A CPU has fewer number cores.The GPU has more cores than the CPU.
The CPU has lesser cores however, each of them is more powerful say each core is 3 GHz. Thus it has few but powerful cores.Although GPU has more cores, each core is less intense than the CPU. The cores might be 0.5 GHz or 1 GHz. Thus it has a lot of weaker cores.
The CPU can only do sequential processing.A GPU can do parallel processing.
Execution time(T)= 1/f x CPI x IC
f= clock frequency
CPI= Clock per Instruction
IC= Instruction count
Execution time(T)= 1/f x N x CPI x IC
N= number of cores
  f= clock frequency
  CPI= Clock per Instruction
  IC= Instruction count
It works on low latency. This means it manages to process high-volume data with minimal delay.GPU aims for high throughput. This means it manages to give more processes within a given period of time.
CPUs are more versatile.GPU is less versatile.
Consume a large part of the memory.Require low memory consumption.
CPUs have an effective speed.GPUs are faster than CPUs.
There were diverse instruction sets.There are few but highly optimized instruction sets.

Conclusion

The CPU is responsible for the serial processing while the GPU is responsible for parallel processing of tasks. Thus for the high performance of the computer both CPU and GPU are required. This will make parallel portions of code run on GPU and serial portions on the CPU.

If seen individually both have their own limitations. A CPU has heavy-weight instruction sets, slow switch latency, and defy Moore’s law. While GPU has less powerful cores, can focus on only one task at a time, has limited APIs.

This all proves that depending on the needs we decide the requirement of CPU and GPU. Neither one is better than the other, both hold equal importance. 


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