I promised some members results of a real world speed test in rendering 4K videos with Creative Suite using OpenCL and CUDA. I also include Windows 10 results. Specs 12 core X5690 24GB RAM GTX980 Yosemite 10.10.5 on Samsung 850 EVO (SATA 3 adapter) El Capitan 10.11.1 on Samsung 850 EVO (SATA 3 adapter) Windows 10 on Western Digital Harddrive All latest Nvidia and CUDA drivers Premiere project and video source files on XP941 SSD formatted as xFAT. Source : True 4K 4096x2160. No audio. 30 seconds length. PHOTO JPEG Codec. Output : Same resolution, no audio, same length. Maximum rendering quality setting. H.264 Codec. Save on the same drive as source footage. Notes : GeForce has no OpenCL support on Windows version of Media Encoder. Results : El Capitan OpenCL : 1:47 El Capitan CUDA : 1:48 Yosemite OpenCL : 2:00 Yosemite CUDA : 2:00 Windows 10 CUDA : 0.32 I had to run the Windows test three times because when I saw the progress bar moving so fast I thought there was something wrong with the settings, but they were exactly the same. You can see from the output file sizes all four renders came out to around 44.8MB. Conclusion : if you work with video using Creative Suite you would save a lot of time using Windows. This isn't news, but it is shocking to see the result above.