What is a Render Farm?
Professional rendering requires processing power not always reachable with just one computer. Modern software allows linking several computers or processors to work as one on various rendering tasks. Such a setup is called a render farm. It can be as small as a normal-sized computer case with a powerful CPU and good cooling system, or as big as a data center full of server racks. Big farms usually provide remote rendering services and are usually accessed only through the internet.
How exactly does it work and what’s even the point? Let’s take a look.
Basic structure
When you only start using 3D, you soon learn that 3D modeling and 3D rendering are two very different processes. The former can be performed on any mid-range PC without much trouble and becomes cumbersome only when the polygon count reaches millions. Photorealistic rendering, on the other hand, is very demanding when it comes to RAM and CPU/GPU power. Either of these components costs a lot of money, which makes it look like large investments are required if you want to pursue 3D graphics professionally. But this is what rental farms are for. These services charge only for the time you use their computers, which is much cheaper than buying hardware.
Some call their rendering computer a render farm, but usually a farm consists of several CPUs or GPUs. We’ll focus on CPU-based rendering in this article. There are processors already designed to work with other similar processors, like the Intel Xeon series. They are installed on special motherboards that house two, four, or even more CPUs. Such setups generally don’t require any specialized software and work as a single computer.
It is also possible to connect several CPUs when each is installed to their separate motherboards. Such computers should be connected together in a network or through the internet. Special farm management software is installed on all of them, for example, Autodesk Backburner. This software divides the tasks through the network to render one image or a sequence at once. In V-Ray, each machine is assigned certain buckets of a full picture. As it finishes rendering them, it sends the data back to the main computer, where the final image is compiled together.
All the computers must have access to a shared drive through which the data is exchanged. This is also where the project files are stored, including textures and caches. The results are also uploaded here and can be accessed online.
Maintenance
Apart from the cost of buying all the components, a farm requires constant maintenance. The main source of potential issues is the cooling system. Powerful CPUs generate massive amounts of heat, and these high temperatures, if unaddressed, may melt the delicate structure of the electronics. Effective air or water cooling sometimes takes up as much space as the actual servers, if not more. This is why many cloud rendering platforms are located in data centers. These are special premises with state-of-the-art ventilation and climate-control systems installed.
Another source of constant expense is electricity bills. Network rendering is an energy-demanding process with a demand for redundancy. Server rooms are divided into clusters, each with a separate fuse box and UPS. This way the computers will have time to shut down safely if the power cuts off and won’t be fried because of sudden surges in the system.
Finally, services based in clouds should be monitored for steady access to the internet. It means having sophisticated tools that can detect malfunctions and either fix them or alert a tech team. Real-time cloud rendering is only possible with fast internet access that won’t drop once more than one person is connected. All of this means free render farms are rare and usually use the hardware the user already has.
Capabilities
All of this effort is for one purpose, fast rendering. It is essential for modern film and VFX industries. Rendering a feature film from Pixar or DreamWorks requires years of processing, but if divided between thousands of processors it only takes a couple of months. Your favorite superhero or a cool car appears on the screen thanks to network rendering. Cloud rendering and similar services are in high demand in game development, VR/AR, and architectural visualization.
A render farm compiles images several times faster than any single processor could. It is also a great choice for those who don’t have the finances to purchase a top-tier workstation. Even with a powerful computer, things like particle simulations and sub-surface scattering take a long time to visualize without the combined CPUs or GPUs. In animation, a single frame rendering time may seem small, but if each takes 5 minutes, a 3-minute clip will be completed in 15 days. The remote render on a farm reduces these times to mere hours.
The best render farm offers fast access, steady uptime, a wide range of software support, and low prices. At Megarender we are aiming for the best cloud rendering a farm can provide. Try our online service for free to make sure it suits your needs.