Category Archives: Article

Why GPU Rendering is an Optional In-App Purchase

Today in 2015, my guess is that only in 1 in 4 customers have Macs whose GPUs are compatible with FA 4 GPU OpenCL rendering. Before Mavericks, almost 100% of Macs (those with Nvidia or ATI GPUs)  could use FA 2’s GPU rendering.
There are multiple OpenCL driver issues causing this and frankly there is nothing that can be done to fix it as a small app developer.
That is why free GPU Trial was put in the app and why GPU rendering is an optional purchase.  We did not want customers to feel they spent money on a broken feature, especially when we have no ability to fix the underlying bugs in Mac OS X’s OpenCL drivers.

Keeping GPU Rendering Support in the Product

When FA 3D was under development in 2012, Mountain Lion was the current of OS X and its OpenCL GPU drivers worked very well. Basically GPU rendering worked on all Macs with discrete Nvidia or AMD (excepting the AMD 4XXX series GPUs) from 2009 and later.

Then Mavericks appeared and OpenCL driver hell began for so many FA customers. FA 3D was released right after Mavericks release. We had no idea that Apple would release such bad drivers and for most Mac models, never fix them. Continue reading Keeping GPU Rendering Support in the Product

State of OpenCL GPU Rendering on Macs in 2015

Fractal Architect is testament to the power of OpenCL powered GPU rendering.

The 2013 Mac Pro OpenCL drivers are world-class and deliver amazing performance. The 2011 and 2012 Macbook Pros are solid GPU rendering workhorses.

The Intel CPU OpenCL driver was greatly improved in Yosemite with a doubling of performance over Mavericks.

It is also serves as a stark reminder of what happens when the OpenCL driver/compiler/runtime provided by Mac OS X is not maintained and bugs are ignored. The Intel OpenCL GPU drivers on the Mac OS X platform are best described as: unusable, broken.

We have no control over the state of these drivers. Apple can do amazing things with their drivers, as the Mac Pro team did. They can also give you a miserable experience, when bug reports are ignored and years go by without useable drivers.

Unfortunately, for most of you having Macs that are powered by Intel GPUs, you will not have the chance of using GPU rendering.

These are the Mac models currently having OpenCL driver issues and a short comment on why they don’t work:

  • All Intel Iris, HD 5×00, HD 4000 GPUs

    OpenCL LLVM compiler targeting those GPU’s can’t compile our kernels.

  • 2014 Macbook Pro with Nvidia 750M GPU

    Automatic GPU switching breaks OpenCL apps. Other Macbook Pro models also use automatic GPU switching, but they work fine.

  • 2010 and earlier Macbook Pros

    GPU rendering worked fine on Mountain Lion. Mavericks and Yosemite drivers are broken/useless.

Apple – you have shown what you can do. Please give attention to your OpenCL driver stack.

Rendering on the new Mac Pro

Update:

The render performance using the Mac Pro’s twin GPUs at the same time varied between roughly 20x and  28x faster than using its very good 6 core Intel Xeon CPU.

When restricted to using a single GPU as the render device, the render performance varied between roughly 11x and  16x faster than using its CPU.

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Continue reading Rendering on the new Mac Pro

To GPU or not GPU Render – That is the Question

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)

Continue reading To GPU or not GPU Render – That is the Question