Blender Cycles X - Render Speed Test in ArchViz Scenes

Just a couple days ago Blender Foundation announced new Blender 3.0. One of the most exciting features in this version is Cycles X - the new incarnation of path tracing rendering engine for Blender. From the first announcements of developers it looks that it is to be much faster than the current version. Is it true? Let's find out!

I conducted tests on PC with AMD Ryzen 3900x, Nvidia Geforce RTX 2080 Ti and 32 Gygabytes of RAM. I set Blender to Optix GPU rendering, although i selected only GPU as my Optix device, AMD Ryzen was not involved in rendering process. Since Blender 3.00 Cycles X branch does not allow you to choose tile size, I used "progressive refine" in Blender 2.92, so tiel size would not affect the render time. 

You can download Blender Cycles X version from Blender site if you choose experimental branch option. You will find "Cycles X" branch on the list. Just download it, extract it anywhere you want and you are set.

Blender Cycles X goal is to:

• improve the architecture of rendering engine for future development,
• improve usability of viewport and batch rendering,
• improve performance on modern CPUs and GPUs
• introduce more advanced rendering algorithms.

Today we will focus on the performance. I will use our Archinteriors for Blender collection as a benchmark. I downloaded it from Evermotion Shop and just drag and dropped blender files to two Blender instances. It's just as simple as that.

The first scene that I am going to test is scene number one from Archinteriors vol. 48 for Blender collection. It is a nice loft with a lot of wooden materials.

Archinteriors for Blender vol. 48 Scene 01

First, I set my render samples to 128. I need to turn off "square" samples option in advanced settings. It increases sample count to the power of two, so when you selected 64 samples and they are squared, in fact you are rendering 64 times 64 samples which is 4096. we don't need as many samples in our test. So I uncheck "square samples" and change number to 128. 

Since the release of our collection, Blendere introduced great viewport and render denoising options, so there is no need for rendering insane amount of samples. 128 is rather low, so we will render our scene in 1200 samples too, just to see the image that can be treated as a final.

One word about denoisers in Blender: in current stable version, which is Blender 2.92 we have three options: NLM denoiser, Intel Open Image denoiser and Nvidia Optix denoiser. In Blender 3.0 NLM denoiser will be removed, because AI based denoisers, like Optix and Open Image denoiser give better results, so there will be only two denoisers in the final version. I will use Optix denoiser in both renders - in Blender 2.92 and Blender 3.0 alpha.

I havent tested CPU performance yet, because with the modern GPU at hand I don't think that CPU rendering on Cycles makes sense, accounting that you have enough of GPU memory. GPU rendering is much faster and it is the future of Cycles in my humble opinion. 

As you can see, it took only 2 minutes and 5 seconds for Cycles X to render our image with 128 samples. for comparison - Blender 2.92 with regular cycles rendered this image for 4 minutes and 30 seconds.  Stunning! The grey part of both bars is the time that it took to load the scene into memory and start rendering. In both case it was just about one minute.

When rendering with 1200 samples, it took 15:35 minutes to cycles X to deliver the image. On the contrary - regular Cycles struggled for 35:15 mintes with this scene. we are talking here about insane gain! This time prefetching the scene took also just about a minute in both cases.

This is a scene number four from the same Evermotion collection. It is also a loft, this time a bit more vintage. 

Again, Blender Cycles X beats regular Cycles version by far. Only 33 seconds for low quality rendering, two minutes 42 seconds for rendering of 1200 samples version and 5 minutes 13 seconds for rendering with 2400 samples. To render this last image, older Cycles version needed over 30 minutes! It means that new Cycles X can be almost six times faster!

Thanks for reading and watching! :)