OptiX support for Cycles and RTX cards is now avaible!

I don’t know if this has been communicated elsewhere, but this little news seems to be very encouraging.



Exciting times ahead…!!?


What is that mean? That gtx cards like the gtx 1080 that I have will support real time ray tracing?

Not real-time in Cycles though, but a significant increase in an overall render speed.

Sure it’s compatible. Whether it’s coming to Blender or not is another matter entirely, as we have plenty of devs saying they’re not even considering it until 2.8 gets wrapped up.

Not for long can still mean over a year :slight_smile:

  • With optix, we will have fast denoising in the Cycles viewport and fina render .
  • With RTX we will have real time raytracing for Cycles and Eevee.

Denoising will be supported by 1080 and above and RTX will only be supported by RTX cards.

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haha… :smiley: Could be true, however… if we could reach somewhere near the extended target goal of Blender Development Fund 2.0, pace of the overall development may change for good and we might expect some implementations earlier than waiting for almost an year or more.

Nvidia only bundles the OptiX raytracer with their drivers. That’s why those can be used within Blender easily without running into licensing issues. That is unfortunately not true for the OptiX denoiser. As of now, there are no signs that the denoiser would be bundled with the drivers.
OptiX 5.1 does not use the RT cores of the RTX cards which provide lots of extra performance. I expect that this is going to be added in the future though. Nevertheless, we should be careful about calling it a realtime solution, because we just don’t know yet how well it is going to perform. There are plenty of signs that Nvidia has overhyped it quite a bit.


I thought OptiX was a denoising thing ? Is it also/only a raytracing thing ? Can someone ELI5 ?

OptiX is generally a ray tracing platform and have been available as SDK for a long time.

AI-Accelerated Denoiser happens to be one of its key features that was introduced with OptiX 5.0 (not long back)

Here is a demo from Pixar, that’s dated more than 5 years ago.


ok, too bad!
It’s really useful on Redshift.

Unfortunately, the OptiX raytracer and the Optix denoiser are different Nvidia products. For whatever reason, Nvidia decided to market them together in a misleading way. For many users, that does not make a difference. In the case of Blender, it definitely does.


Alright thanks for the clarification. Is it “Embree for GPUs” ?

It’s a bit of a marketing mess - there’s OptiX, which is a framework for developing renderers on GPUs, there’s OptiX Prime, which is essentially Nvidia’s Embree, and there’s the OptiX denoiser, which is completely unrelated.

Also, OptiX raytracing works on all CUDA GPUs, not just RTX - on the others, it just does the raytracing in software.

As mentioned in the general Cycles thread, don’t expect wonders - I can guarantee that it won’t be anywhere close to realtime in Cycles, I’d be surprised if the average speedup was more than 2-3x (still nice ofc). It’s not even realtime in games, they just denoise the hell out of 1spp renders which is why raytraced reflections sometimes end up looking like badly compressed JPEGs.

On non-RTX cards the impact will be even smaller since the current Cycles BVH code is already based on Nvidia papers - no doubt that their engineers can optimize more, but on the other hand you’ll probably get some conversion overhead.


It looks like, a bit of words of rebuttal have started (or maybe not) on the same tweet thread. :smile:

Does anybody know what this OB (for the score) stands for, and on what criteria this overall benchmark is calculated?

Another question, they claim… OptiX + RTX can’t match up the speed of Vulkan + RTX. Isn’t OptiX for CUDA using RTX would have a better performance than writing ray-tracing for Vulkan with RTX, as the former (combination) being under one umbrella of and optimized for NVIDIA GPUs?


Back in the days Vlado (Chaos Group) had also reported better performance on VRay GPU with OCL vs CUDA.

OB, OctaneBench, like cb is the score unit for CINEBENCH 15.

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I hope AMD soon comes up with an Optix alternative for AMD GPU owners, so Cycles can also support that.

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Just remember to take anything OTOY say with a grain (maybe a bucket full) of salt. They don’t have the best reputation in this industry, especially when it comes to speed and benchmark claims…

OTOY, Jules (CEO), developers… are very, very different things. Usually it’s Jules who is a little bit off. :wink: