GPUs are parallel processing units that perform high-end computations and are used in a variety of fields, including game graphics. Advances in GPU technology are enabling more realistic graphics and faster computation speeds, and are being applied to a variety of devices, including smartphones.
As the gaming market has evolved in recent years, so has the technology involved. If you look at the graphics of the latest games, you’ll notice that they’re so realistic that they’re almost indistinguishable from reality. They’re also able to run at 144 frames per second, or even higher resolutions to produce high-quality visuals. To run these high-end games smoothly, the performance of your graphics card is crucial. Inside a graphics card is a circuit called a graphics processing unit (GPU). The GPU’s main task is to render 3D models. Rendering is the process of using a computer program to create an image from a model or a file called a scene, which is made up of models. The more powerful the GPU, the higher the quality of the image. GPUs are optimized for these rendering operations. In this article, we’ll first explain how GPUs work and what they’re used for, and then cover the rendering techniques that GPUs are responsible for, such as Anti-Aliasing, Ambient Occlusion, and Ray Tracing.
A GPU is an electronic circuit designed to rapidly process and transform graphics-related operations, accelerating the generation of images in a frame buffer for output to the screen. Today, GPUs are used in devices such as cell phones, personal computers, and video game consoles. GPUs speed up the processing of applications by taking over the computationally intensive parts of running an application and passing the rest of the work to the CPU. GPUs are similar in name to central processing units (CPUs), but the two computing devices work very differently. First, CPUs perform computations in a serialized manner. Serial processing is the execution of one instruction at a time. For this reason, CPUs are composed of four to eight cores that are optimized for serial processing. GPUs, on the other hand, perform computations in parallel. Parallel processing involves executing multiple instructions simultaneously. GPUs are composed of thousands of cores that are optimized for parallel processing.
You might be wondering which tasks use the CPU and which use the GPU. The truth is that many of our favorite tasks, such as writing documents, surfing the internet, and calculating, can be handled by the CPU alone. However, when it comes to tasks like gaming, the situation is different. Games often feature dynamic scenes, such as car crashes, flying debris, building collapses, and bomb explosions. To make these scenes look smooth and realistic, you need to perform physics and particle effects computations simultaneously to draw realistic graphics. If the CPU were to handle these tasks alone, it would be overwhelmed, and the visuals would not be as good as we expect. This is where GPUs come in. By sending tasks like physics, particle effects, and graphics rendering to the GPU, we can get much higher quality results in less time than if the CPU were to do them alone.
As the name implies, GPUs are primarily used to perform graphics-related computations. Also, GPUs cannot be used as universally as CPUs because their design removes circuitry for general-purpose computations and uses and adds circuitry for specific computations. However, due to the efficient parallelism of GPUs, there have been attempts to apply them to general computations. This is called General Purpose Computing on GPU (GPGPU) technology. GPGPU is a method of sending parallel computations to the GPU that are performed by the CPU when running a general program. This was made possible through improvements such as expanding the programmability of GPUs and adding parallel computation algorithms to the design of computer applications. Today, GPGPU technology is used in a wide range of applications, from specialized software for analyzing molecular structures and predicting weather changes to our favorite media player software. It’s also used in many video conversion programs.
In addition to GPGPU technology, there are other uses of GPUs outside of graphics computing. These are cryptocurrency miners. Cryptocurrency mining is the act of creating blocks that record the history of cryptocurrency transactions and earning cryptocurrency in return. In the early days, the difficulty of mining was not very high, so it was possible to mine with just a CPU. However, as the difficulty of mining increased, it required a device that was much more efficient than a CPU, and the parallel computing power of GPUs led to the rise of GPU miners.
Now let’s take a look at the rendering-related technologies that GPUs are primarily responsible for. The first is anti-aliasing, which minimizes stair-stepping: when a high-resolution image is scaled down to a lower resolution, the edges appear jagged, a phenomenon known as stair-stepping. There are several ways to minimize this stair-stepping. A common method is to enlarge the screen you want to render by a factor of 4, then divide the enlarged pixel into 4 smaller pixels, recomputing for each smaller pixel, and then downscaling to the original resolution. This method is called 4X Supersampling Anti-Aliasing (SSAA). While this method is simple in principle, it has the disadvantage of being computationally intensive. A complementary approach is Multisampling Anti-Aliasing (MSAA). The principle is similar to supersampling, but because it only finds and calculates the parts of the 3D model where the boundaries of the 3D model cross, the number of color calculations is smaller than in SSAA. This means that the GPU is less computationally intensive, but the degree to which staircasing is resolved is smaller than in SSAA.
Ambient Occlusion (AO) and Ray Tracing (RT) are both rendering techniques related to light sources. Ambient occlusion is a technique that approximates the attenuation caused by light blocking; in other words, it creates a realistic scene by making places like corners and gaps darker. Unlike ambient occlusion, which is concerned with shadow representation, ray tracing is concerned with light reflection. Ray tracing is a technique that tracks the rays of light entering the observer’s eye to represent their color. Ray tracing is divided into two main types based on how the rays are tracked. One is forward ray tracing, and the other is backward ray tracing. Forward ray tracing is a technique that tracks the light emitted by a light source in a granular way. This has the advantage of more faithfully reproducing natural phenomena, but it’s also inefficient because it has to track light that doesn’t reach our eyes. Unlike forward ray tracing, backward ray tracing uses our eyes as a starting point and traces light in the direction of our gaze. The advantage of ray tracing is that it provides realistic visuals, but the disadvantage is that it places a huge computational burden on the GPU. This has made it difficult to use in real-world games and 3D visuals. However, with the latest RTX series graphics cards, the RT cores responsible for ray tracing computations have been added to enable efficient parallelization. As a result, we can expect to see more realistic videos using ray tracing in the future.
Current-generation GPUs have reached the point where physics effects, light effects, particle effects, and more can all be applied to a 1920×1080 resolution screen more than 60 times per second. However, it is difficult to achieve the same quality 60 times per second at 4K UHD (3840×2160) resolution with current GPUs. As people demand higher and higher resolution screens, there will be a greater need for GPUs that can seamlessly deliver high-quality video at higher resolutions.
GPUs were originally only found in graphics cards, but smartphones started using them to process high-quality photos quickly, and now almost all smartphones have GPUs. In the future, there will be many new smartphones with GPUs, which will greatly improve the performance of smartphones. As GPUs continue to become more and more sophisticated, we can expect to see these technological advancements continue for years to come.
