There is a huge amount of CUDA middleware while there is very little for OpenCL. In the case of deep learning, there's cuDNN which is highly optimized and used

There is a huge amount of CUDA middleware while there is very little for OpenCL. In the case of deep learning, there's cuDNN which is highly optimized and used by all major frameworks. AMD has promised something equivalent, but a first version is very unlikely to have the same scope and features. (Nvidia probably does a large amount of dog fooding given their deep learning based automobile efforts.) Using anything but Nvidia for deep learning is a great idea if you want to get noticed for not using Nvidia for deep learning, but it wouldn't be the smart thing to do if you want to actually get something done.