Fractal Noise vs. Turbulent Noise render speed comparison

[synthetick]

Hi, I’m investigating speed differences between Fractal Noise and Turbulent Noise. There’s a lot of decade-old videos on YouTube and documentation on the web saying that Turbulent Noise renders faster than Fractal Noise. Even the most-up-to-date official AE help pages say that "The Turbulent Noise effect takes less time to render." ( https://helpx.adobe.com/after-effects/using/noise-grain-effects.html )

However that is not my experience at all on my M2 Mac Studio running AE 2025, where Turbulent Noise performs worse than Fractal Noise. I have significantly faster (up to 3 times faster) renders with Fractal Noise versus Turbulent Noise. An Adobe Community thread from 2017 mentions that Fractal Noise was a new addition to the GPU accelerated family in 2017. ( https://community.adobe.com/t5/after-effects-discussions/fractal-noise-bug/td-p/9294540 ) I examined my GPU usage in Activity Monitor and found that Fractal Noise utilizes my GPU much more effectively than Turbulent Noise.

So I'm wondering whether most of the online info about Fractal Noise's performance is outdated. Would anyone be able to share their own experience of Fractal Noise vs. Turbulent Noise render speeds?

And side question: Which effect do you prefer? The controls are almost identical but I personally go for Fractal Noise because of the seamless looping option. However Turbulent Noise "more accurately models turbulent systems, with smaller noise features moving more quickly than larger noise features" according to Adobe's documentation.

[Warren Heaton]

Hi @synthetick:

It's always worth comparing render time for similar effects.

I just applied Turbulent Noise to a 5 second MP4 video file that's Layer 1 and Fractal Noise to the same video that's Layer 2.

Looking at the Composition Profiler with each effect applied at the default settings without any keyframing, Turbulent Noise results in the layer rendering in 1ms while Fractal Noise results in the layer rendering in 18ms.

Pictured: Composition Timeline showing the Render Time for the same source footage with Turbulent Noise and Fractal Noise applied.

This is on a 16-inch MacBook Pro M4 Max 128GB/4TB.

What are you seeing for Render Time under the Comp Profiler and are you able share a download link to your test project?

- Warren

[synthetick]

Thanks for testing this, that’s really interesting. Since my original post I delved a bit more into AE’s development history and discovered that originally Fractal Noise was CPU-only and slow. Turbulent Noise is newer but CPU-only, and faster than the old Fractal Noise. (This is what all the outdated documentation still refers to.) HOWEVER, after AE 14.2 (2017), Fractal Noise became GPU-accelerated, with a huge performance jump. Turbulent Noise stayed CPU-based and did not catch up.

Regarding your test results differing from mine, one key difference might be that your test uses MP4 footage with no animated evolution, whereas my tests are on solids with continuously evolving noise at 4K, which forces a full procedural recompute each frame. In those cases Fractal Noise seems to benefit heavily from GPU acceleration, and I'm seeing a basic Fractal Noise outperform a basic Turbulent Noise by about 7x on my Mac Studio.

Out of curiosity, do you see the same profiler results if you animate Evolution or Offset continuously on both effects?