As the effects of global warming and other environmental concerns become evident, sustainability has become increasingly important for the global technology sector to consider. In particular, the cryptocurrency mining boom highlighted the extremities of what poor practices can lead to. At its peak in 2021, cryptocurrency mining consumed more energy than some small countries in a year. Thankfully, energy use of this kind has slowed, but it leaves the remaining users of high-energy servers with their own questions about energy-use ethics and sustainability.
Those within the computer graphics industry face this very question when it comes to rendering 3D scenes. Whether rendering locally or using a render farm, creating high-fidelity renderings comes with energy costs. In this article, we’ll be looking at the current state of rendering in the cloud, the sustainability of render farms, and how we can work towards a lower carbon footprint for our industry.
The energy use of render farms is an important concern for the sustainability of rendering. 3D rendering can be one of the most intensive tasks for a server to compute, requiring massive amounts of raw CPU/GPU power and power for HVAC systems to keep server rooms cool. A single RTX 4090 GPU can consume up to 450 watts of power, not including CPU, system, or cooling energy costs. Scaled to the size of a render farm, the energy consumption can be massive.
The good news is, that despite the growing energy requirements of computer hardware, the efficiency of computer hardware has grown at an even faster rate, especially when it comes to server equipment. Over the years, hardware providers and server/render farm operators have worked towards more efficient hardware as a way to minimize costs and increase the productivity of equipment. The byproduct is, that although the demand for servers has drastically increased over the past decade, the energy use has largely remained flat. According to a study published in Science, demand for server computing tasks has grown 550%, while energy consumption for these tasks has only grown 6% from 2010 to 2018.
However, despite the increased efficiency of server farms, the fact remains that rendering still requires massive amounts of power, and there are still ways that artists and render farm providers can help cut energy use.
Optimizing plays a huge role in the overall energy use of a render farm. It all starts with the project being rendered. A faster rendering image generally will mean lower energy use for that render. So before sending your scene off for rendering, checking that you’ve fully optimized the project for your specific quality needs will save energy in the long term.
On the farm side, render farm providers can also help reduce energy use by optimizing the hardware and software setups of their render nodes. For example, grouping projects to be rendered on a single render node can often be more efficient than using dedicated render nodes for each submitted render project. Assuming a well-optimizing algorithm for render job sorting, this kind of project grouping can be minimally slower than dedicated render nodes.
Where energy is spruced from is also an important factor for the sustainability of render farms. A server farm that runs on renewable energy sources will have a much lower environmental impact even when using equal energy to farms running on non-renewable energy. Practically speaking, render farms can pursue this goal by building and running their server farms in areas that have access to high amounts of renewable energy.
For small farms or studio render farms, controlling energy acquisition can be difficult, however, asking your energy providers about how they are implementing renewable energy can be an important step towards using renewable energy yourself. Furthermore, for large rendering projects, using an online render farm that sources its energy sustainably can often have a lower environmental impact than rendering projects locally. The efficiency of online render farms combined with a renewable energy source can be sufficiently more environmentally friendly than other options.
Carbon offsets are another way artists and render farms can reduce the overall environmental footprint of rendering. Carbon offsets, while not ideal for long-term sustainability, can help when other sustainability options aren't available or aren’t fully in place yet. Carbon offsets allow individuals or render farm providers to fund environmental projects to reduce overall carbon emissions. Carbon offsets often fund the development of renewable energy or forest restoration projects.
Many render farms already purchase carbon offsets as a way to reduce their overall carbon footprint. Individuals and artists can also purchase offsets for their rendering projects, which can be important if you render your work locally or have your own home/studio render farm.
Apart from energy use, waste is a critical environmental factor for render farms. Render farms run on hardware that needs constant updates to stay current with the latest rendering technologies and render speeds. This can lead to older yet still functional hardware being replaced and discarded, leading to a massive amount of electronic waste (e-waste). Electronic waste can contribute to landfill usage, and the high turnover of equipment can be environmentally costly due to the materials and energy required to produce new hardware.
There’s no easy solution to the e-waste problem. On one hand, new hardware tends to be more efficient, thus leading to lower energy use. On the other hand, discarding perfectly functional servers and hardware is wasteful. However, some solutions can minimize the impact of e-waste. One solution is to promote the repurposing of old equipment for other server tasks that require less cutting-edge hardware. Selling old equipment to third parties, or even using old render servers internally as test machines or web servers can help reduce the problem.
In the end, there is no single solution for reducing the environmental impact of rendering. Instead, a successful approach will require careful use of rendering technology and hardware to reduce the effect that the computer graphics industry has on the environment. The good news is, a sustainable industry is possible. With a little work from artists and a lot of work from render farm providers, rendering could become a net benefit for the environment through careful energy sourcing, carbon offsets, and a green e-waste policy.