The drive for perfection of visual effects and digital scenes over the years has resulted in growing demands for more powerful equipment to manage and control lighting, shadows, geometries, textures, and an ever-expanding list of features that industry-leading rendering software offer. And with those demands, the GPU has become more important than ever. Keep reading to find out why GPUs are important, what to consider when buying a GPU, and how they are different from rendering engines.
CPU vs. GPU
The standard central processing unit (CPU) that controls every operation and instruction in computers, often gets saturated or overloaded when carrying out complex calculations during the rendering process.
In order to overcome these rendering challenges, the graphic processing unit (GPU) was introduced to the market to assist CPUs with rendering tasks. GPUs help accelerate image generation and digitalization through the use of multiple cores within integrated chips. They support larger data blocks working alongside the CPU, thereby optimizing the rendering process.
GPUs are in charge of manipulating and displaying graphics, and work independently from the CPU. Most GPUs on the market work with a specific rendering method called rasterization. This method consists of decomposing geometries into pixels to be displayed on computers and other digital devices. The more detailed and specialized the rasterization is, the better the image quality that can be obtained from the rendering process.
Types of GPUs
Integrated GPUs are located or built-in alongside the CPU and share the same RAM. They are affordable and consume less energy, however, they tend to have lower performance than discrete GPUs.
Discrete GPUs are separated from the CPU and process operations and instructions independently from the CPU with their own RAM memory. They offer better performance and are more suitable to process graphic data than integrated GPUs.
However, discrete GPUs require high energy consumption, generating residual heat that needs to be controlled to maintain an appropriate functioning computer. A discrete GPU is more suitable for professionals in the gaming or audiovisual industry.
GPU Specifications and Characteristics
When choosing a GPU, it’s advisable to know the specifications of graphics cards and how they impact the rendering quality and efficiency.
GPUs use video random access memory (VRAM) instead of the standard RAM that a CPU uses. The VRAM stores data temporarily while carrying out the rendering process. The GPU needs to store large amounts of data to convert them without needing assistance from the CPU’s RAM. Hence, the VRAM limits the number of frames the GPU can render at once. When the GPU runs out of space, the CPU generates low-quality images with lower performance.
As a general rule, VRAMs should have a capacity of at least 12GB to generate high-resolution images and detailed textures. Of course, a larger RAM demand will depend on the purpose of the GPU (gaming, animation, mining, etc).
GPU Clock Speed
GPU clock speed represents how fast the multiple cores in the GPU work to render images. The speed is represented in gigahertz (GHz) and determines the GPU’s performance when gathering data.
The clock speed depends on the rendering demand and the complexity of the tasks assigned to the cores. It’s measured in GHz because it’s related to the amount of rendering cycles the GPU can perform in one second.
Memory bandwidth represents the amount of data the GPU can copy and transfer to the graphics processors in a given time. The memory bandwidth unit is gigabytes per second (GB/s). It’s as important as the VRAM in terms of GPU specifications since it represents how quickly the data flows, affecting the rendering efficiency.
Popular GPU Brands and Manufacturers
Since rendering performance depends highly on the graphics card’s specifications, it’s important to be aware of which GPUs are best for different rendering purposes and the different brands and types of GPUs that are available on the market.
Generally, the most popular GPU manufacturers are NVIDIA, Intel, and AMD. However, there are still a few other competitors that are offering high-quality solutions.
Some smaller companies rely on their partnerships with GPU manufacturers to offer graphics cards with NVIDIA, Intel, or AMD chips but with modifications to the cooling system and other settings. Here’s a short list of popular GPU brands and series available on the market.
- PowerColor from AMD
- RTX series from NVIDIA (Quadro and GeForce)
- Sapphire from AMD
- XFX from AMD
- ZOTAC from NVIDIA
- ASUS with combined technology (NVIDIA and AMD)
- MSI with combined technology (NVIDIA and AMD)
GPU Rendering Engines
GPU rendering relies on the hardware to render images, contrary to rendering engines, which generate images regardless of the hardware by using different rendering techniques such as ray tracing.
Some GPU rendering engines use a single GPU to generate their images, but most updated options use a multi-GPU engine to render faster and better. The most popular GPU rendering engines on the market include plugins to integrate the efficiency of hardware rendering with the versatility of software rendering.
Popular Rendering Engines
Redshift (Redshift Rendering Technologies)
Redshift is the most popular rendering engine for the motion picture industry, supporting a variety of rendering software such as Cinema 4D, Blender, Houdini, and Maya. It works with NVIDIA GPUs and ray tracing technology.
Octane Render (Otoy)
Octane Render supports multi-GPU rendering with high-resolution graphics at a high rendering speed. It works with a variety of GPU brands such as NVIDIA and AMD, and includes software plugins from Cinema 4D, Blender, Houdini, and Maya.
Blender Cycles (Blender)
Blender Cycles was developed by the open-source rendering company Blender. It offers a free rendering engine with a variety of visual effects and settings, supports NVIDIA GPUs, and offers Blender plugins to create photorealistic models.
Iray was developed by GPU manufacturer NVIDIA. This rendering engine uses intuitive technology to generate photorealistic models and high-resolution visuals. It supports NVIDIA hardware and multi-GPU rendering for cloud-based rendering solutions as well. Iray includes software plugins for Maya, 3ds Max, and Rhinoceros 3D.
Arion is a hybrid rendering engine that combines GPU and CPU rendering power. It requires NVIDIA GPUs to render high-resolution images. This rendering engine focuses on digital photography and includes limited software plugins (3ds Max and Rhinoceros 3D).
GPUs and Application Programming Interfaces (APIs)
Application programming interfaces (APIs) enable the link between the hardware (GPUs) and the software in terms of computing elements and carrying out the programming needed to render models. The APIs work as programmable platforms to enhance GPU performance and control the GPU’s instructions to surpass hardware rendering limitations. There are three main API technologies used with GPUs.
CUDA is one of the most innovative APIs on the market. It works with C/C++ and Fortran languages to facilitate programming. CUDA is both a low-level and high-level API depending on the model and was developed by GPU manufacturer NVIDIA to extend bandwidth memory and optimize rendering calculations.
OpenGL is a low-level API whose purpose is to accelerate the rendering process through a cross-platform. This API is language-independent, making GPU programming a difficult task. It was the first commercial API developed for gaming and visual effects but it has restricted rendering functions. However, it’s an open-source platform, making it an affordable and competitive option. OpenGL separates desktop rendering from mobile rendering by using two different platforms.
Vulkan is the successor of OpenGL, with the purpose of computing 3D graphics in both CPUs and GPUs with high performances. It was specially developed for multi-GPU rendering to optimize the rendering process and task distribution. This API was built to work with AMD GPUs to provide affordable rendering options and unify desktop and mobile APIs while still providing higher GPU control.
Render Pool Cloud-based GPU Rendering
Understanding GPU functionality and specifications is key to choosing the ideal hardware and rendering software for your needs. Fortunately, Render Pool’s services take into consideration the best GPU options, combining hardware and software performance to boost your design projects and provide an efficient and competent online rendering solution.
Render Pool’s infrastructure combines Blender Cycles rendering engine with AMD’s Radeon and GeForce RTX GPU technologies to render photorealistic and high-resolution models. They provide multi-GPU rendering with popular software plugins such as Maya, Blender, and Houdini to facilitate your modeling workflow and achieve professional results.
Since Render Pool is a cloud service, designers and animators can work on projects remotely in the comfort of their homes or offices, without risking resolution and quality of rendering projects on local workstations.
If you have an upcoming deadline on your next design project and don’t want to sacrifice quality for speed, be sure to try Render Pool’s best-in-class cloud rendering service!