What is an Accelerated Processing Unit?

An Accelerated Processing Unit (APU) is a 64-bit microprocessor that combines the processing potentials of a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit) in a single chip. While APU sounds like any normal computer chip, it actually is solely used by AMD like the brand name of the CPU/GPU combo chips they manufacture. To better understand what an APU is, it is best to have a little background on the two processors that it merged.

As the brain of the computer, the CPU is the main processing unit that receives and executes instructions from computer software or application. Similarly, it sends out instructions to other parts of the system, telling them what to do. It is the most crucial part of a computer system, without it, the computer is basically dead.

The GPU has similar functions as the CPU, but it only processes graphics-related information and renders graphical content. If a computer without a CPU is dead, a computer without a GPU is blind, with no video output.

In most systems, the CPU and GPU are two separate entities. There isn’t really a problem with this except that the data transfer rate will improve if the two processors are closer to each other. Furthermore, these two units operating at the same time results in higher power consumption, and AMD didn’t turn a blind eye to this. In 2011, they introduced their first high-performing and power-efficient processor that combined the advantages of the CPU and GPU into one, single chip, popularly known today as the APU.

Evolution of APU

AMD, as a leading manufacturer of computer electronics, has been transpiring structured and efficient architecture for their CPUs and GPUs. The APUs they have created is usually a merger of their existing CPU and GPU designs. The resulting processor performs better than the average CPU and GPU combined. Before it was known as APU, it was first branded as the “Fusion”. Due to a trademark infringement issue, the term was later on changed to APU.

AMD designs two types of APU, one for high-performance devices and another one for low power devices. The first generation APU for high-performance devices featured K10 CPU cores and Radeon HD 6000-series GPU and was codenamed, Llano. Likewise, the first APU for low-power devices featured the Bobcat microarchitecture and a Radeon HD 6000-series GPU and was codenamed, Brazos. In 2012, AMD released Trinity, the second generation of high-performance APU, and Brazos 2.0, the second generation of low power APU. The APU continued to progress as AMD’s CPU and GPU architecture advanced, with performance as the core of each enhancement. Succeeding generations featured the latest architecture at that time, and each iteration bagged numerous improvements over the previous one. Aside from performance, AMD also improved on upgradability. While earlier releases inhibited future CPU upgrades this was made possible starting with the APU Ryzen series. The 2020 release, Renoir, is based on Zen 2 core architecture and Vega 8 graphics.

APU continues to evolve to this day, and with recent and more advanced architectures from AMD, the release of the next generation of APU is imminent.

Benefits over CPU + GPU

The APU’s game-changing technology is a significant development in the computing industry, and it has several advantages over the CPU + GPU setup.

Better performance. Blending CPU and GPU in the same chip improved the data transfer rate significantly since they are now using the same bus and sharing the same resources. APUs also support OpenCL (Open Computer Language), a standard interface for parallel computing, which utilizes the computing power provided by GPUs. With its multi-core, CPU and GPU, tasks that require the high processing power of a CPU and the fast-image processing of a GPU can take advantage of the performance an APU can offer.

Power-efficient. Combining two chips into one does not only save space but saves power as well. Aside from improving the APU’s performance, AMD also consistently works on reducing the power consumption of the chip despite it already being low power. The recent releases feature low Thermal Design Power (TDP). For example, Ryzen Embedded 1102G features the lowest TDP of only 6W.

Cost-effective. Price is probably the biggest advantage of AMD’s APU over CPU and GPU tandem. With a price tag of ~$100 to ~$400 depending on the features, purchasing an APU generally costs cheaper than buying a CPU and a GPU separately. Though the higher end units are quite pricey, they’re still considerably cheaper than the price of CPU and GPU combined with the same level of performance. This also holds true for future upgrades. Since AMD is now lax when it comes to upgradability and compatibility of APUs, users can save a lot with just a one-chip upgrade compared to upgrading both processors.

Is it a Better Processor?

APUs have been used across different devices such as desktops, laptops, servers, mobile devices, and game consoles. This heterogeneous chip has been patronaged by businesses and consumers for a decade. But can it really replace CPU and GPU? Ultimately, it would depend on the user’s needs and demands.

Consumers, PC builders, and gamers on a budget can turn the benefits of APU to their advantage. Most APUs can provide decent performance. In fact, it can outperform the performance of mid-range CPUs and GPUs. It’s a perfect choice for users who don’t really demand intensive use of graphics and the highest possible performance from a CPU. It will also do great for home and office standard PCs. AMD continues to develop more advanced APUs, and recent releases are already capable of supporting graphics-heavy tasks.

However, when it comes to extreme gaming, an APU won’t suffice. It’s still not able to compete with the graphical experience that high-end discrete graphics cards can offer. For low-budget, entry-level PC building and gaming though, an APU would be an ideal alternative.

APU cannot completely take the place of CPU and GPU, but it is a fitting high-performance, power-efficient alternative in many cases. As AMD’s designs continue to advance and new technologies continue to emerge, it would come as no surprise if the future generations of the APU can fully replace both CPU and GPU.

About the author

Glynis Navarrete

Glynis Navarrete

A freelance blogger who loves to write about anything related to technology. Born and raised in the Philippines and worked in Singapore for eight years as Technical Support for a wide range of IT equipment. Took a dive into the world of freelancing and now enjoying doing what I’m passionate about while not losing touch with technology.