Avoid the error CURAND failure 201

You are probably running on a Pascal GPU (for example a GTX 1080) with CUDA 7.5. You need to upgrade to CUDA 8.0 (and then build and link CNTK from source against CUDA 8).

Also if you are using a binary installed version of CNTK, check whether it was compiled/linked with CUDA 7.5. All versions up to and including 2.0 Beta 2 are linked against CUDA 7.5 and will not work with Pascal GPUs.

TODO: list some helpful steps for people to transition from 7.5 to 8

Windows

You should set the environment variable CUDA_PATH_V8_0 and the environment variable CUDA_PATH

setx           CUDA_PATH "C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0"
setx      CUDA_PATH_V8_0 "C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0"

before opening visual studio. The build process should work seamlessly. If you have compiled CNTK in the past with CUDA 7.5 you might have to reload the MathCUDA project.

Linux

TODO