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)
Mavericks 10.9.1 has a change that breaks the cached OpenCL rendering code for users using the Intel Iris Graphics GPUs. This change does not affect Nvidia or ATI discrete GPUs. Intel CPU based rendering is unaffected.
News Update (Jan 15, 2014): All 3 apps have been updated for this issue.
All 3 apps have had an update sent to Apple which fixes the problem. Apple’s Christmas shutdown for all App reviewers will delay the mandatory review by Apple. So you may not see the free update on the Mac App Store until the New Year or so.
Fixed in version 2.2. Finder quicklook plugin did not work. This ATI GPU generation was not suitable for high-performance OpenCL rendering. (ATI 5xxx and later generations are fine.)
Plugin no longer uses GPU for rendering.
2008 Model Dual CPU Mac Pro
Color gradient editor does not work. This turned out to NOT be a bug.
Resolved: This was due to a corrupted User Preference file. Deleting the user preference file for Fractal Architect fixed the problem.
