Quick Tips for Faster Cycles Renders in Blender

How to speed up Blender's Cycles render engine
How to speed up Blender's Cycles render engine

Table of contents

How can I make my cycles render faster? That is the question in every Blender artist and animator’s mind. We’ll look at a couple of methods for making cycles render quicker while still producing clean renderings.

NB: If you are looking for ways to speed up the new Cycles X render engine, go through the following tips ‘How to speed up Blender’s Cycles X rendering’

1. Optimize your sampling and denoising settings

The following are the Blender sampling settings that I use on my projects by default. They not only produce clean renders, but they also cut my render times in half.

How to optimize sampling settings in Blender
How to optimize sampling settings in Blender
  • Go to Properties Editor > Render Properties > Sampling tab
  • Set ‘Render’ to between 128 and 200
  • Set ‘Viewport’ to 32
  • Activate ‘Adaptive Sampling’ by checking the box
  • Set ‘Noise Threshold’ to 0.01
  • St ‘Min Samples’ to 0
  • Under ‘Denoising’ subtab, activate ‘Render’ by checking the box and set it to ‘Optix’. Activate ‘Viewport’ and set it to ‘Optix’
  • ‘Start Sample’ set to 0
  • Go to the ‘Advanced’ subtab. Set ‘Seed’ to 0 and click the clock icon
  • If you do not have any transparent material in your scene, set the Min Light Bounces, Min Transparent Bounces and Light Threshold to 0,0 and 0.01 respectively

2. Optimize light path settings

The following are the Blender light path settings that I use on my projects by default. They not only produce clean renders, but they also cut my render times significantly. I adjust them slightly depending on the materials and light sources in a scene. But these work on most projects.

How to optimize light path settings in Blender
How to optimize light path settings in Blender
  • Go to Properties Editor > Render Properties > Light Paths
  • Total – 4, Diffuse – 3, Glossy – 3, Transparency – 3, Transmission – 3, Volume – 0
  • Under ‘Clamping’, set the parameters as follows: Direct Light – 0.00, Indirect Light – 10.00
  • Under ‘Caustics’ set ‘’Filter Glossy’ to 1.00. Activate both ‘Reflective’ and ‘Refractive’

3. Enable GPU rendering in Blender’s user preferences settings

GPU rendering allows you to use your graphics card instead of the CPU to render. This can speed up rendering because modern GPUs are built to handle a lot of number crunching. They do, however, have certain limits in producing complicated scenes due to relatively restricted memory, as well as difficulties with interaction when utilizing the same graphics card for display and rendering.

How to enable GPU rendering in Blender 2.79

  • On the top left corner, click File > User Preferences
User preference settings tab in Blender 2.79
User preference settings tab in Blender 2.79
  • On the popup, click System in the top right corner
How to enable CUDA GPU rendering in Blender 2.79
How to enable CUDA GPU rendering in Blender 2.79
  • On the Bottom left, select CUDA and check the box to select your GPU
  • Then Save user settings

How to enable GPU rendering in Blender version 2.9 and 3

  • On the top left corner, click Edit and go down the tabs and click Preferences
User preference settings tab in Blender 2.9
How to change Tile Size in Blender version 2.9 and 3
  • On the popup’s left menu, go down to System
How to enable CUDA GPU rendering in Blender 2.9
How to enable CUDA GPU rendering in Blender version 2.9 and 3
  • Choose CUDA on the top menu and then check to select your GPU

4. Optimize your render tile size

Changing the “Tile Size” is another way to reduce render times. What exactly are tiles? Tiles are the small boxes that appear on your screen as Blender renders. Tiles allow the processor to focus on a smaller portion of the scene while saving memory, resulting in fewer or no crashes.

Best tile size settings for CPU and GPU rendering in Blender
Best tile size settings for CPU and GPU rendering in Blender

Surprisingly, the fastest CPU render time is also the slowest on the GPU. This is because the GPU can only render one tile at a time and thus does not benefit from more tiles. To summarize, the best tile size for GPU is 256 x 256. It’s 16 x 16 for the CPU. If those don’t work, try keeping it in the power of twos (e.g. 128, 256, 512, 1024), as the processor handles these faster. Below is a guide on how to change Tile Size in Blender.

How to change tile size in Blender 2.79

Under render properties, go to the Performance Tab

How to change Tile Size in Blender 2.79
How to change Tile Size in Blender 2.79

How to change tile size in Blender 2.9

Activate the ‘Auto Tile Size’ addon. Same as in Blender 2.79, under render properties, go to the Performance Tab. Copy the settings in the image below.

How to change Tile Size in Blender 2.9
How to change Tile Size in Blender 2.9

5. Activate the Persistent Data feature. Persistent Data is available from Blender 2.93 and above

Blender 2.93 got a major rendering update called Persistent data.

This is how it works: When you press the render button, your scene is calculated and cached on the first frame. The frames that follow rely on the first frame’s cached data. These can sometimes increase the speed of your renders by up to 5 times. Because elements in your scene are no longer calculated in every frame as they were previously.

Limitations of Persistent data

Persistent data performs best in static scenes. Scenes in which no objects are moving. An interior architectural rendering, for example. As of now, the Persistent data feature does not support caching animated objects in the scene.

Persistent data comes at a cost of increased memory usage.

How to activate Persistent data

Under render properties, go to the Performance Tab then the subtab ‘Final Render’

How to activate Persistent Data in Blender 2.93
How to activate Persistent Data in Blender 2.93

6. Optimize your HDRI multi-importance sampling

When working with high-res hdr environments, Blender can become very unresponsive when initially loading hdri. The reason for this is the time it takes to build an importance map that cycles needs in order to avoid fireflies during rendering. The importance map tells cycles where the bright areas of the hdri are so that it can favor those join rendering and produce a better result.

To optimize your hdri multi-importance sampling, go to the World settings > Settings tab. Change ‘Sampling’ from Auto to Manual. Now adjust the ‘Map Resolution’ value accordingly. You just need to set it high enough to avoid fireflies but low enough for Blender to respond incautiously. From my experience, values of 512 and 1024 work best for me.

How to optimize your hdri multi-importance sampling in Blender
How to optimize your hdri multi-importance sampling in Blender

7. Set a render region when working on shading or lighting of a single object

You can improve viewport rendering tremendously when shading or lighting a single object. Because cycles will concentrate all resources on the render region instead of the whole viewport. Since a selected render region is smaller than the viewport, cycles will render the region faster.

To select a render region, click Ctrl+B. Then with your mouse draw a box around the object you would like to view as rendered. Below is a .webp to help you select a render region in Blender.

How to select a render region in Blender
How to select a render region in Blender

8. Upgrade to Blender version 3 to render in Cycles X

What is Cycles X?

To put it simply, Cycles X is a collection of improvements for the Cycles render engine. The ‘X’ stands for the 10 years cycles render engine has been in existence. Users have reported Cycles X to be up to 30 times faster than its predecessor Cycles render engine. Of course, it depends on the scene settings.

Below is a graph comparison between Cycles in Blender 2.93 and Cycles X in Blender 3.0 on different test scenes by the Blender Foundation.

Render speed graph comparison between Cycles and Cycles X render engines on different scenes by the Blender Foundation
Render speed graph comparison between Cycles and Cycles X render engines on different scenes by the Blender Foundation

To use Cycles X render engine, you need to download and install Blender version 3. After installing, Blender will ask you if you would like to keep settings from your previous Blender version, which you should accept.

For tips on best render settings for Cycles X, read through ‘How to speed up Blender’s Cycles X rendering engine’

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