iGPU vs dGPU vs tGPU vs APU

Graphics are very important in today’s computer age. However, despite how common it is to use computer graphics for GUIs, for video games, etc., the truth is that it is becoming more and more complex, especially when iGPUs, dGPUs, APUs and now tGPUs appeared. But don’t worry if all this confuses you, in this article you will learn what all this is and their differences…

What is a GPU?

A GPU (Graphics Processing Unit), or graphics processing unit, is a type of modern chip that is capable of rendering 3D for video games and other applications. For this, the data and instructions that arrive at this chip are processed to render, that is, to create the graphics. In the past, graphics work was also overloaded on the CPU, but with the advancement of graphics quality, this put a huge overhead on this unit. That is why the first graphic accelerators emerged, to make way for what we currently know as graphics cards or GPUs.

A GPU is capable of performing a multitude of mathematical calculations per second to calculate the correct values for millions of pixels dozens or hundreds of times each second. All computing devices, from PCs to smartphones, have a GPU.

What is an iGPU?

Many laptops, and also some desktop and AIO PCs, come with an integrated GPU or iGPU. This type of unit is in the same packaging as the CPU, albeit on a separate chip as can be seen in the image above. These graphics fulfill their function, generating the necessary graphics, although they are not as powerful as dGPUs as we will see later.

In addition, another thing must be taken into account, and that is that when there is an iGPU, a dGPU could also coexist on the same computer. They are not incompatible, but can serve as a complement.

What is a dGPU?

A discrete GPU, dedicated GPU, or dGPU, is a graphics processing unit that is not part of the CPU, that is, it is implemented in a separate package or on a separate PCB. Some dGPUs are simply soldered onto the motherboard itself, others are mounted on modules like MXMs. In either case, it will also be accompanied by VRAM memory chips. Therefore, you will not need to make use of the shared RAM.

Unlike a graphics card, which includes a more complex PCB and also includes the cooling system, a dGPU is slightly different. Also, as I said before, a dGPU can also coexist with an iGPU.

The dGPUs that come built in to the motherboard are not easily replaceable, as it would involve desoldering the BGA from the GPU and replacing it with another GPU. But this is expensive and special equipment and laboratory are needed. On the other hand, those found in MXM modules for laptops can be easily replaced as you would do with a conventional graphics card from a desktop PC.

Another consideration is that dGPUs don’t typically need extra power from the PSU like high-end graphics cards do. In the case of the dGPU, when they are integrated into the motherboard, they get their power through it.

I also would not like to forget that the dGPU is not exactly the same as the GPU that comes with graphics cards. Between NVIDIA, AMD, and Intel’s GPU models for the desktop and their chips for laptops (Mobile), there are slight differences, especially in the TGP, which is lower, and also the performance is often somewhat lower. Keep in mind that they have to make the battery last…

What is an APU?

Just like Intel embraced iGPUs in its processors, AMD did something different by using the term APU (Accelerated Processing Unit). In this case, the GPU can also be considered integrated, but unlike a conventional iGPU, in this case it is integrated on-chip, that is, within the same chip as the CPU. Therefore, everything is a monolithic chip.

In other words, the APU could be considered something intermediate between the iGPU and a SoC, since it integrates the GPU on the same chip as the CPU as the SoC does, but it would not be an SoC, since it lacks other additional units that if they are typical in SoCs.

The first APUs arrived in 2011. This technology was originally known by AMD as Fusion, and it was intended to revolutionize the market with a chip with heterogeneous architecture, although it ultimately did not turn out as expected. Of course, currently there are still APUs to compete with the Intel line that includes iGPUs.

Being in the same die, it has benefits in terms of performance when the CPU must tell what to do in the GPU. However, as with the iGPU, in this case there will be no dedicated VRAM either, instead the CPU and GPU will have to access and share the same RAM.

GPU design comparison

  • Graphics card: We refer to a PCB board that includes the GPU chip, as well as VRAM memory chips, BIOS, and all the necessary auxiliary elements, such as ports, power socket, cooling system, etc.
  • GPU: It refers only to the graphics processing unit, that is, the central chip. It manipulates and alters memory to create images in a frame buffer that can then be output as video to a screen. It requires other components to function.
  • iGPU: It is a GPU integrated in the same packaging as the CPU. The iGPU works the same way as a GPU, but all the cooling, ports, memory, etc. are taken from other components.
  • APU: It could be said that it is like an AMD iGPU, but that it is included in the same monolithic chip as the CPU. AMD APUs support Heterogeneous System Architecture (HSA), which allows the CPU and GPU to be on the same bus, thereby reducing communication latency.

If graphics performance isn’t important to you, since you’re not going to be gaming intensively or doing other heavy graphics tasks, then an iGPU or APU is best.

If performance is very important to you, because you are going to render or play AAA titles, then a dGPU for laptops or a graphics card for desktop PCs is ideal.

When consumption is critical, an APU or SoC is better than any other unit. If power consumption isn’t critical, you could use any kind of graphics unit. When power scaling is important, a graphics card with multi-GPU setups in mind is best.