Flam4CUDA for Mac and Fractal Architect have supported fractal rendering on the GPU since 2009. Flam4CUDA for Mac (I am its author) was an open source precursor to Fractal Architect.
Fractal Architect 3D, FA 2, and Serendipity all use the powerful OpenCL platform to render on either a CPU or a GPU. On OS X Mavericks, all recent Mac GPUs from Nvidia, ATI, and Intel are supported.
The beauty of rendering on the GPU is quite simple: Speed !! (speed varies by GPU model)
For example, rendering on Macbook Pro laptop GPUs is often 3 to 4 times faster than rendering on the CPU. With the new Mac Pro, the speed increase might be 100X times faster (not benchmarked yet as of late 2013 – but this speed increase has been seen with Flam4CUDA on high end gaming PC’s)
The disadvantage is the possible presence of bugs in the OpenCL drivers and OpenCL code compilers. OS X updates can bring new driver bugs without warning, which force me to update the apps. For example, Hotfix for Mavericks 10.9.1. But usually these problems are short lived.
Summary of OpenCL Rendering Issues for OS X Mavericks
[table]
Device,Performance,Compile Speed
Intel CPU,Slow, 2 secs. Fast
Intel Iris GPUs,Slow to Moderate,2+ mins Very Slow!!
Nvidia GPUs,Very Fast,15 secs.
ATI GPUs,Very Fast,5 secs.
[/table]As of Mavericks version 10.9.1, unfortunately we consider the Intel Iris Graphics GPU OpenCL driver to be of only Beta quality because OpenCL compile’s time out at 2 min 20 secs followed by an app crash. The only workaround is to create smaller variation sets. The OpenCL drivers for the CPU and Nvidia and ATI GPU’s don’t have this problem (see table above).
Render Performance
If you want to submit your Mac’s render performance, just render the fractal called Worlds.fa that is in FA 3D’s Gallery to a PNG file with size 1440×900 pixels at 300 render quality. Please post a comment with your results.
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GPU
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Render Time
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GPU/CPU Peformance
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15″ Retina Macbook Pro – Mid 2012
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Nvidia GT 650M
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4.93 sec
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325% X Faster than CPU
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Intel(R) Core(TM) i7-3720QM CPU
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16.08 sec
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Baseline CPU
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Intel HD 4000 GPU
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79.78 sec
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496% X Slower than CPU
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Macbook Air Mid 2013
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Intel HD 5000
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34.485 sec
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30% Faster than CPU
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Intel(R) Core(TM) i5-4250U CPU
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44.923 sec
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Baseline CPU
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Macbook Pro Early 2011
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ATI 6750M
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8.74 sec
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242% Faster than CPU
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Intel(R) Core(TM) i7-2720QM CPU
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21.08 sec
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Baseline CPU
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27” iMac Mid 2010
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Intel CPU
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39.707 sec
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Baseline CPU
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I tested this on my iMac with 3.5 GHz i7 and NVIDIA GeForce GTX 780M with 4096Mb VRAM.
It took 16 seconds using CPU, and only 2 seconds with GPU. That’s without installing any CUDA drivers, using the “Like Classic Flam3 v 3.0” setting.
Pretty amazing performance running this way!
Random generation with GPU is very fast but produces very lov qulity images. How to get better quality?
Same things happen when rendering, I need to rerender some images using CPU.
I use Macbook pro and I mac with Yosemite.
The app is optimized for fast preview renders when creating/editing new fractals. Of course, you can do extremely high quality long renders too, but not while editing. Think of it as “draft” mode while editing for fast turnaround.
The app was tuned for responsiveness on Macbook Air’s. More powerful Macs can use higher render quality defaults for editing.
The default quality settings are changeable under Preferences.
See:
Preferences > Thumbnail Grids > Triangle Editor, Quicklook, Grid Thumbnails quality settings.
Preferences > Preview > Minimum Quality
GPU rendering quality is greatly improved in Fractal Architect 3D compared to FA 2 or Serendipity.
Some fractals (a small percentage) do not converge well and have a lot of noise in their images. For these few fractals you will want to increase the quality settings mentioned above.
With final production renders, the quality is so high that render noise is insignificant.
Editing quality is usually between 35 and 50, while final production render quality will range between 3,000 and 10,000.
Also, you might play with the Gamma Threshold parameter setting if you are getting areas of your fractal with a lot of noise.
Some fractal will have noisy regions even with extremely high render quality settings.
FA 3D allows you to change quality related parameters after after a long production render and quickly post-process the fractal again. So you can tune the Gamma and Gamma Threshold settings then