These render performances were measured using Fractal Architect 3D version 3.1.1.
This version has the fixes for the image artifacts described here:
http://www.fractalforums.com/macintosh-fractal-software/fractal-architect-3d-fractals-done-the-mac-way!/msg70176
Apple released version 3.1.1 earlier today.
Note: These are machines are all Apple laptops. These are not desktops.
Fractal Architect 3D 3.1.1 on Mac OS X Mavericks 10.9.1Worlds.fa 1440 x 900 Render Quality 300 - It is a 3D fractal included as a fractal example in the app's Gallery.
15" Retina Macbook Pro Mid 2012 ==============================
This has a quad-core i7 CPU (with integrated Intel Iris HD 4000 GPU) + a separate discrete Nvidia GT 650M GPU.
Intel HD 4000 GPU 74.561 sec 4.46 X Slower than CPU <=== Slowest Device on this Mac
Nvidia GT 650M GPU 4.675 sec 3.58 X Faster than CPU <=== Fastest Device on this Mac
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz 16.716 sec Baseline CPU
Macbook Air Mid 2013 ====================================
This has a dual-core i5 CPU (with integrated Intel Iris HD 5000 GPU). No discrete GPU.
Intel HD 5000 GPU 32.388 sec 1.40 X Faster than CPU <=== Fastest Device on this Mac
Intel(R) Core(TM) i5-4250U CPU 45.34 sec Baseliine CPU
Macbook Pro Early 2011 ==================================
This has a quad-core i7 CPU + a separate discrete AMD 6750M GPU.
Tested on Mountain Lion 10.8.5 running on Thunderbold 2.5” Seagate external HD
ATI 6750M 6.623 3.62 X Faster than CPU <=== Fastest Device on this Mac
Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz 23.957 Baseline CPU
Using the 2D test fractal used in the prior post. 800 x 800 Render Quality 5000
Retina Macbook Pro Mid 2012 ==============================
Intel HD 4000 GPU 408.577 sec 2.26 X Slower than CPU
Nvidia GT 650M GPU 50.481 sec 3.59 X Faster than CPU
8.09 X Faster than HD 4000
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz 181.097 sec Baseline CPU
Commentary ======For the 2011 and 2012 Macbook Pro's, the rendering performance advantage of a discrete GPU over the CPU is approx. 3.6X or 260% faster.
The Intel HD 4000 integrated GPU (2012 models) renders substantially slower than the CPU core on the same processor.
The Intel HD 5000 integrated GPU (2013 models) renders faster than the CPU core on the same processor - for a dual core Haskell i5.
I don't have a 2013 13" Macbook Pro to test with, but I suspect its quad core CPU will be faster than its HD 5000 GPU.