Lets be frank. Apple’s OpenCL drivers are in terrible shape in El Capitan.

On a 2015 Macbook Pro with AMD Radeon M9 370X GPU, renders are 45% slower than Yosemite 10.10.5. Metal is no alternative as its compilers can’t handle the app’s kernels on AMD GPUs.

On a 2012 Retina Macbook Pro with Nvidia 650M GT GPU, the OpenCL driver crashes the app in a function named LaunchGrid. In earlier OS X versions 10.7 through 10.10, the OpenCL drivers on this Mac were rock solid. Also Metal does not work for this GPU either.

OpenCL on Intel GPUs have never been able to compile the app’s kernels (except during Mavericks 10.9 Beta).  Metal does work on recent Intel GPUs, but a persistent GPU hang issue caused by that implementation, is a serius critical issue.

I apologize to my customers. I have no control over the quality of Apple’s OpenCL and Metal drivers.