Differences Between APU, CPU, GPU and iGPU on a PC

APU, CPU, GPU and iGPU are four terms that we use practically every day in the hardware world, and that for those who are not very knowledgeable in the matter can be confusing. For this reason, in this article we are going to explain what each of them is, and of course what their differences are.



Actually, in this world of hardware we are forced to use many acronyms, acronyms and anglicisms to facilitate communication, but on many occasions they are so many that they can lead to confusion. Among these terms, without a doubt APU, CPU, GPU and iGPU are the most used (in addition to RAM, of course), so to avoid confusion we will explain what each of them is and how they differ.

APU, CPU, GPU and iGPU, what do they mean?

It is mandatory to start at the beginning, since these four terms are only acronyms or acronyms that come from English, but each one refers to a different and specific hardware component.

  • APU : Accelerated Processing Unit, or accelerated processing unit.
  • CPU : Central Processing Unit, or central processing unit.
  • GPU : Graphics Processing Unit, or graphics processing unit.
  • iGPU : Integrated Graphics Processing Unit, or integrated graphics processing unit.

AMD-APU

Many of you will say: a CPU with iGPU is an APU, and you are right but not quite, so we will explain it in detail below, but in the simplest possible way to make it understandable.

What are the differences and why are they so called?

Let’s start with the basics, the CPU. The CPU is the processor of a PC, the “brain” in charge of carrying out all the operations and that controls everything that happens in the system.

On the other hand we have the GPU , which is the “processor” that the dedicated graphics cards incorporate and that, unlike the CPUs, its set of instructions and internal components are optimized for graphics . Although a CPU can perform the majority of operations (not all) of a GPU and vice versa, since they are not optimized for this, the performance is substantially lower, which is why they are two separate components.

CPU-vs-GPU

In other words, the processor is dedicated to the general operations that a PC needs to perform, while the GPU is dedicated entirely to calculations related to the graphics we see on the screen, such as generation of scenarios, polygons, etc. To perform these calculations, they incorporate different hardware inside, and their set of instructions is also different.

Some CPUs can incorporate a graphics processor in the same die, called iGPU , which is nothing but an integrated GPU but it works independently. In this way, it is achieved that without the need for a dedicated graphics card we can view the content on a monitor, although in these cases the performance is quite low due to the physical limitations they have.

Intel-iGPU

As a variant of the CPUs with iGPUs, in 2011 AMD launched the APU concept, which differs from these in that the graphics hardware it integrates is not only significantly more powerful (in fact, AMD sells them as gaming devices), they have a fundamental difference, the HSA (heterogeneous) architecture .

Thus, the difference between an APU and a CPU with iGPU is that in an APU the calculation cores (CPU) share data directly with the graphic cores (iGPU), being able to use one and the other regardless of the type of operations we are performing in the PC at all times. In short, an APU has an HSA architecture and that simplifies the number of steps that must be taken to complete any instruction.

APU de AMD

If we have to make a very crude and simple summary of what each of these terms is, we would say the following:

  • CPU: is the processor, which is in charge of the daily operations of the PC.
  • GPU: it is the graphics processor, in charge of everything related to these.
  • iGPU: it is a small graphic processor that is integrated within the same die as the CPU.
  • APU: In AMD systems, it is a CPU with iGPU that has a heterogeneous architecture to improve performance.