In the past few years the market for a render farm service has increased to meet the growing need for fast deliverables in the CG industry. Big render farms created by movie studios existed earlier but they were separated from the outside world by slow internet connection. The increase of internet bandwidth made the computing centers accessible from any computer connected to the Web, starting the boom of all cloud services, especially for rendering computer graphics via online render farms.
An online render farm is an ideal solution for freelancers and studios who need access to more rendering power on demand. The time spent uploading and rendering combined will be far shorter than rendering a whole frame range on a workstation or even a few machines. You could even send a single image over to a farm, where it will be divided into strips that will render in parallel and merged to the final frame after. Time is money, after all, and, cloud render farms are the ultimate time saver. Besides that, they also spare you the headache from:
More often than not, a render farm service would provide plugins that can integrate into your software, making it just another tool you’d add to your production pipeline.
Just like any CG tool, rendering on a farm isn't a magic button that will get you the results you want in a single click. While indispensable for client work, render farms can also leave you with unusable frames and a burning hole in your wallet if you don't take some necessary precautions. The better you know a tool, the more you gain from using it.
This guide will help you avoid making rookie mistakes, and get familiar with the tool, so that you can use cloud farms efficiently and make the most of your time and money spent on rendering.
Every render farm service should give information about their pricing as a price per hour of rendering on one node, Ghz hour, or some other measurable unit of node usage. This information is good to have when trying to get a general idea of the cost, but will only ever be an approximation at best and won’t tell you what the precise cost of rendering a specific project would be.
This is why many render farms offer cost calculators. A cost calculator is a tool that helps you get a scene cost estimate before making any commitment to the service.
Render farms cannot predict how much a project will cost you just based on the animation’s length, the number of frames or output resolution. It’s technically impossible. That’s where cost calculators come in.
The way they work varies from render farm to render farm, but is generally quite easy to follow. Cost calculators generate an estimate of the cost of rendering of a project by comparing speed benchmarks of a farm’s processing power against yours. They multiply this ratio (farm speed vs. your speed) by the average time of rendering one frame on your computer, the number of frames, and finally by the rendering cost per time unit. Let’s take a look at some examples.
The example above shows a calculation of the total rendering time of a scene on a farm. The cost of rendering such a scene is based on the resulting total time, and multiplied by a cost rate.
Based on the total rendering time we got in the first example, we can now calculate the cost of rendering.
The cost of one hour of rendering will depend on a service and the plans or priorities they offer. In addition to those, some render farms offer volume discounts and special packages for larger payments. These discounts often don’t lower the price itself but give additional render credits on top of what you paid for.
This system can be an enormous cost saver in the long run and is especially beneficial to studios with high rendering needs.
In the above example, a general cost rate for one hour of rendering with 1Ghz speed is multiplied by the power of the specific processor. The result is a cost rate for rendering with the given processor for one hour.
Render farms will often use “Ghz Hour” as a unit of billing. This particular way of presenting the cost rate is more universal and often easier to use when comparing different farms. In many cases, render farms are built from nodes which use various types of processors and so the final cost rate depends on their speed.
The equation above shows how much time your job will need to finish rendering – from the moment your project finishes uploading to farm to the time when the last frame is completed.
It depends on several factors:
*does not apply to server rental models and the like
Cost calculators are good tools for getting a very rough estimate of the cost of rendering, but they should be treated as an initial benchmark for the render farm cost for your project.
Cost Calculators do not take into consideration factors like a project’s loading time, troublesome frames that need re-rendering or the time needed to calculate a GI cache, among other things. This is why render farms often put a disclaimer next to their calculators, indicating that the final price can be somewhat higher or lower.
To understand more let’s have a look at how an online render farm works.
Online render farms are big sets of fast servers and nodes with fast internet connection.
They are put together from new models of computers to maximize speed and optimize electricity usage. However, farms don’t need to upgrade all their nodes to the latest cutting edge technology every month. The power of an online render farm lies in the scalability and parallelism in network rendering.
Nowadays, you can render a project on the cloud in a number of ways:
All options have their advantages and disadvantages:
A cloud render farm service model is the more popular option because of the level of automation and the availability of support. From a user’s point of view all projects go through a few stage process on cloud rendering as a service. Let’s take a closer look at what this service model entails.
Scene dependencies, like paths to external assets, need to be modified to match the farm’s system. Render farm plugins do this for you, and in some cases even provide render presets for specific scenarios that would require a different render setting for network rendering than what you’ve prepared for your local machine
After initial preparation, the scene is uploaded to a farm using a plugin feature which works similarly to an FTP uploader.
If the farm doesn’t use a plugin at this stage of the process, the projects ( scenes and all assets ) need to be prepared manually according to farm’s guidelines and uploaded by FTP or a similar tool.
After you upload your scene to a cloud render farm and launch your job, it gets sent to the farm’s node network by render management software. Depending on your project’s volume, it takes less or more time to load it to all cloud nodes. Render farms take care of this problem by optimizing their network for speed.
The management software then tells each node to load your scene on its respective 3d program. This part is also dependant on the scene’s size. As you probably noticed on your own computer, opening a scene in 3d software can sometimes take time. It doesn’t always depend only on the scene and asset volume though, every 3d program has its ‘style’.
This part of the rendering process is not taken into consideration by cost calculators. You can compare the rendering time by comparing the benchmarks, but only as far as the time between the start and end of rendering. Your scene’s loading time can differ from what you experience on your computer. In the case of remote servers, the scene is ready to render right after uploading, and you set up the rendering yourself, just as on your local computer.
No matter which cloud service you choose, the scene will be rendered on different types of computers and software environments than yours. 3d applications and render engines can use the processor’s features in a different way than your hardware setup does, so some random variation in render times may appear. It’s good to take it into consideration when you use online calculators.
When frames are ready, they are downloaded to your computer via a farm’s download application, FTP or file sharing service.
At this point, it’s clear that the process of rendering goes through quite a few stages. Even if the farm’s software is simple to use, there is a lot going on under the hood. A scene is taken from your pipeline and set on a farm’s computers. All render farms try to prepare a setup which will be as universal as possible, but they are still a different environment than from where your scene was created.
A render farm’s job is to save your time, but since it’s a very technical service it’s good to check some things ahead, so when you are in a hurry you can start rendering in no time.
The best way is to run a one frame test of your scene, and it doesn’t have to be the final version of the project. If you have an early version or just a scene which uses the same 3d software features, it will help you filter out potential problems and allow you and the farm make necessary tweaks, if they are needed (the final version will still need to be tested before final rendering though).
If you are using assets downloaded from the internet, they can sometimes cause issues in rendering. Professional online shops like Evermotion create good, ready to render models, but if you are downloading from unconfirmed sources the models can have empty paths or shaders from different render engines which can cause issues during rendering. It’s good to make sure that the models have no paths pointing to non-existent textures or shaders from different render engines.
All render farms are upfront about the 3d software they support, and they usually have a more or less detailed list on their websites.
However, the number of plugins and software builds used out there is so huge that you should double check if the farm can actually render with your specific version.
If you are still unsure, you should try contacting the support team, and ask if they support your exact version, especially if you are using some obscure, very old, or experimental builds. This will also allow you to check if the farm is ready to upgrade or downgrade their software for you, and on what terms. That also concerns any kind of customization of the render farm workflow should your pipeline need it.
Finally, a simple test won’t hurt :)
Before rendering on a render farm, you should pay particular attention to certain features and perhaps take a moment to check their User Agreement. It is usually displayed during the registration process. There are several topics that are especially important:
Like any cloud service, all render farms protect their users’ data, and this is an important part of the User Agreement. If you need an additional guarantee, you can sign an NDA ( Non-Disclosure Agreement ) with a farm. If you don’t have your version of such an agreement, farms usually have their own template that you can use.
If you are going to render a big project or you want to commit to the service long term, it’s good to check your farm’s discounts or other special incentives. Those can make cloud rendering much cheaper.
It’s good to check if the payment methods which are suitable for you are supported by farm. It might happen than certain kind of bank transfers or services like PayPal are forbidden in your country and the farm needs to come up with a different solution. That also includes invoicing for your payments.
Some render farms support charity causes or run special programs for artists and studios by offering them their rendering services for free or just for electricity costs.
As with many businesses, rendering services also have periods of higher and lower traffic. Those are usually vacation periods, or at times right after important industry deadlines, like releasing seasonal holidays ads.
If you are not in a hurry with your personal project or want to ask for help with a charity video, these low seasons are a good time to ask. Farms have more idle nodes to share, and since queues are shorter, you can render on cheaper priorities without waiting too long.
The first contact with online renderfarms can be confusing. There are many services out there, with different workflows, but as with any CG tools, it just takes some testing and getting used to before you will use them with ease.
The first step is to check the software support and pricing. At this stage, you can compare pricing rates per Ghz or use a cost calculator, but the latter doesn’t take into account many factors which affect the final cost. I recommend treating the numbers they give with some reserve.
It’s good to test the water some time before uploading the final project for production rendering. Sending a test scene through the farm’s pipeline will filter out issues on every stage, and will make the process smooth when the deadline is nearing.
In the second part of this guide, we will show you proven testing techniques which give very close cost estimates and help to quickly detect possible problems. They are the real cost, time and stress savers, and I learned them working with hundreds of render farm customers.
To learn more about in-depth testing strategies go to Part 2.
This guide has been created by Michał Moś and edited with the help of the team at GarageFarm.NET. We derived most of the knowledge used in this guide from an extensive experience running a render farm for almost a decade.
Michał Moś ( aka ‘Andrew’ ) is part of GarageFarm.NET team specializing in 3d rendering topics from animation and troubleshooting to technical writing. He has worked for numerous design and architectural companies as a CG artist, designer, and instructor. Weapon of choice – 3ds Max, C4D, V-Ray and Octane. He loves drawing, creative writing, and tabletop RPGs.