Fractal Architect 4 Help Index
Applies to:FA 4
See also: GPU Trial Rendering Window
Some of you will find that even though your Mac has a GPU that is OpenCL compatible, it is unusable by the app.
Many older Macs do not have a OpenCL compatible GPU, so this discussion does not apply to those Mac models. All Macs are capable of OpenCL CPU rendering.
As will be explained below, there are critical defects in Apple’s OpenCL driver/compiler/runtime components that only affect certain Mac models. We cannot fix them - we cannot workaround these defects.
With Fractal Architect 3D, GPU rendering was provided as part of the app. Affected customers were angry that they paid for an app whose most important feature was broken.
With Fractal Architect 4, customers whose Macs are incapable of GPU rendering will not have paid for that capability. You now have a free, risk-free utility to try out GPU rendering before deciding to purchase the option.
Fractal Architect 4 is a very demanding app for OpenCL driver robustness and compatibility. You might find that your Mac model and OS X version together are incompatible with Fractal Architect 4 GPU rendering.
Use the builtin free [GPU Trial Rendering] utility to test you Mac’s compatibility with Fractal Architect 4’s GPU rendering. It allows you to test GPU rendering on a selection of 16 fractals. You can render the same fractal using first the CPU, then the GPU. You can compare image quality side-by-side and see the GPU performance advantage (if any).
This free utility is a risk free way for you find whether your Mac can use GPU rendering or not.
If GPU rendering works great there, you can be confident that it works with your own fractals. If the GPU Trial does not work or crashes the app, you will know that GPU rendering does not work on your combination of Mac and installed OS X version.
Our experience is that most Macs with ATI or Nvidia GPUs can use GPU rendering. Note: Older Macs (2010 and earlier) might GPU render properly on OS X Mountain Lion, but not on OS X Mavericks nor OS X Yosemite.
Right now Intel Iris GPUs won’t work for FA GPU rendering because of an OpenCL compiler defect in all update versions of both Mac OS X Mavericks and Yosemite. The OpenCL LLVM compiler is unable to produce a useable output in a reasonable amount of time, so the OpenCL runtime aborts (killing the app itself). Update: In OS X 10.10.3, the OpenCL runtime no longer aborts. But the underlying compiler problem is still there.
You will experience one of these outcomes:
Future OS X updates OpenCL Driver updates might fix these compatibility issues or might cause new issues on Macs that are now currently compatible. We have absolutely no control over this and we have no way to predict what Apple’s engineers might do in the future.
For instance, customers with 2011 Macbook Pros had to wait 4 months until the Mavericks 10.9.2 update was released, to be able to use Fractal Architect 3D GPU rendering on their ATI GPUs. On those same Macs, GPU rendering on the prior OS X Mountain Lion was very robust. Backwards compatibility regression can happen.
In late 2013 these were the numbers of different configurations of OpenCL capable Macs:
72 different OpenCL compatible Mac configurations in late 2013
Today that number is around 90 different configurations. When you account for all the 5 versions of Mac OS X supporting OpenCL with their multiple updates, the compatibility test matrix is HUGE.
Now does it make sense why the Apple OpenCL platform has compatibility issues?
We only have 7 test Macs. That’s why we don’t know which Mac configurations are compatible and which are not.