[gmx-developers] GTX 680 non detected on OS X

[Uliano Guerrini]

On OSX 11.5 I instelled cuda 7.5, compiled samples and when I run:

./deviceQuery Starting...

 CUDA Device Query (Runtime API) version (CUDART static linking)

Detected 1 CUDA Capable device(s)

Device 0: "GeForce GTX 680"
  CUDA Driver Version / Runtime Version          7.5 / 7.5
  CUDA Capability Major/Minor version number:    3.0
  Total amount of global memory:                 4096 MBytes (4294508544 bytes)
  ...

and so on, so I presume my CUDA installation is correct driver is ok and card is supported. Then I compiled from source using openMP enabled clang from macport (the one from apple is useless and gcc isn’t supported anymore by NVIDIA on OSX) configuring with: 

cmake ../gromacs-5.1.2 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DGMX_GPU=on -DCMAKE_PREFIX_PATH=/opt/local  -DCUDA_TOOLKIT_ROOT_DIR=/usr/local/cuda

All goes apparently well, apart from:

-- Could not detect NVIDIA GPUs

and:

-- Could NOT find NVML (missing:  NVML_LIBRARY NVML_INCLUDE_DIR) 

which I presume I can ignore as on OSX platform NVIDIA doesn’t offer NVML and GPU detection is based on that library (I also read on the net of people safely ignoring these warnings).

Nevertheless when I run gmx mdrun I get the following message:

NOTE: Error occurred during GPU detection:
      CUDA driver version is insufficient for CUDA runtime version
      Can not use GPU acceleration, will fall back to CPU kernels.

My limited abilities (just some printf here and there) led me to find that the call to cudaGetDeviceCount on line 602 of the file gpu_utils.cu within gromacs/gmxlib/gpu_utils of the untarred 5.1.2 gromacs version fails.

Any suggestions?

uliano