One of the biggest decisions you must make when running a business in the VFX, animation, or graphic design industry is which image rendering method to adopt. Historically, high-definition image processing depended on the CPU rendering process. But GPU rendering has in recent years become more popular.
So, which of the two rendering processes is better? The reality is that the two share numerous similarities and each has its advantages. But there are key differences as well.
To help you make a decision regarding which of the two to use in your studio for your project, we’ve prepared this comprehensive guide on both rendering solutions.
What Are CPU and GPU Renderer Engines?
Graphics are generally processed through CPU or GPU rendering machines. But the way each processes tasks is different. Let’s take a close look at each microprocessor.
CPU, or central processing unit, is a component in your computer that’s designed to convert data to information. It executes numerous tasks, one of which is image rendering. A CPU renderer engine is the computer hardware that performs computations needed for 3D graphics.
Given that CPU renderer was the historically available rendering machine, its usage is widespread. It’s no wonder that this option is the industry standard.
GPU, or graphics processing unit, is designed mainly for image rendering. You can use this microprocessor to offload certain tasks from the CPU, which allows the computer to run faster. Besides rendering, the GPU can also perform mathematical calculations quickly for other tasks.
Over the years, GPU rendering machines have become more common. And thanks to their advanced image rendering technology, they now offer legitimate competition to CPU renderers.
What Is the Difference Between CPU and GPU Rendering?
CPU and GPU rendering engines differ in the way each handles tasks. Typically, the CPU will handle various calculations to process tasks. Conversely, a GPU microprocessor can focus all its computing abilities on one task.
What’s more, CPUs consist of up to 24 cores that tackle sequential serial processing. In contrast, a GPU uses thousands of cores that are smaller and more efficient and which can handle numerous tasks simultaneously.
Certain programs can overwhelm your CPU, especially if they’re graphically intense. These applications tend to slow down your computer’s performance. The latest GPUs have the greater processing power and more memory bandwidth compared to traditional CPUs. Thus, GPUs can process tasks much faster. In fact, using GPUs is up to 100 times faster than CPUs when it comes to rendering.
CPU Rendering – What Are the Advantages?
There are many reasons people still use CPU renderers. Here are some of them.
CPUs Can Handle Complex Tasks
Generally, CPUs outperform GPUs when it comes to complex tasks. A GPU is designed to process huge data batches by doing the same thing quickly and repeatedly. This processing power can only be harnessed optimally when GPU cores are performing the same operation at the exact same time. Keeping wings in sync when processing different images is almost impossible. A CPU can handle this smoothly.
The vast majority of graphics cards come with 12 GB memory as the maximum storage. This memory will be filled up in no time if you run a busy studio handling multiple projects at any given time. The typical computer system memory can be as high as 64 GB. The worst thing that can happen when you exceed the maximum memory is your computer slowing down.
When your computer crashes, chances are the problem is caused by the graphics card. This card is among the least stable components of a computer. Where you’re using a purely CPU-based renderer, you don’t need to worry about crashes. Such renderers rarely have hiccups, thanks to their stability.
CPUs offer unquestionable output quality. Thanks to their precision, you can expect better results when you use these renderers as opposed to GPUs.
While a GPU-based render can process multiple keyframes quickly, the render will need extra licenses to extend the processor’s memory. This can raise compatibility issues when it comes to the graphics card. Using a CPU renderer is a more hassle-free option. All you need is to add render nodes to your main CPU renderer, which is an easy process.
Is GPU Better for Rendering?
GPUs may have come later than CPUs, but they’re taking over the imaging rendering field. Here are some of the reasons:
Faster Image Rendering
GPU–based rendering technology is much faster than CPU rendering. Since a GPU’s core processors greatly outnumber those of a CPU, one GPU renderer can easily outperform as many as 20 CPUs.
With a GPU renderer, you can produce top-notch designs without having to pay huge sums of money to a CPU rendering firm. Freelance designers can easily process highly sophisticated rendering tasks, including glossy reflection and depth of field. It’s easy to produce studio-quality images at a tiny fraction of the cost of a CPU-based solution.
A CPU rendering machine generally has separate maintenance and power overheads. With a GPU renderer, these issues aren’t there. You can easily and affordably upgrade the solution without worrying about extra maintenance and power costs. Besides, GPUs are generally more energy-efficient.
GPU Tech Is Constantly Improving
GPU technology has continually evolved, getting better with time. That means any GPU limitations today, such as limited memory, will inevitably be solved soon.
Ideal for Rendering Intensive Graphics
Graphic intensive tasks, such as game creation, image processing, 3D visualization, and deep machine learning, can be performed using GPUs.
But Does CPU Affect GPU Rendering?
Not necessarily. Where you’re strictly rendering with GPU only, your CPU only matters for the tasks you pre-render, such as BVH building. As soon as you start the actual rendering, all the load is handled by the GPU, all the way to the completion of the image and its compression by the CPU.
Note that you can also render on both CPU and GPU simultaneously.
Verdict: CPU vs. GPU Rendering: Which Is Better?
Hopefully, you now know the difference between CPU vs. GPU rendering. But how do you choose the better rendering solution for your project?
That entirely depends on your specific needs. Note that GPU isn’t meant to replace CPU. Rather, GPU enhances infrastructure that’s already existing.
Choose what works for you, and enjoy your rendering.