(Mac) Dreaded "no CUDA-capable device is detected" on 10.13.1 / CUDA 9 / GTX 980 eGPU

I had this setup working previously on macOS 10.12 and some earlier version of CUDA, but I have since upgraded to 10.13.1, and am struggling to set it up again.

I have a Thunderbolt 3 eGPU housing a GTX 980 connected to my Mac. It is successfully enumerated and listed in the system’s hardware tree. I also have the following drivers installed:

  • CUDA Driver Version: 9.0.222
  • GPU Driver Version: 10.27.6 378.10.10.10.20.107

Along with that, I installed the CUDA SDK 9.0.176, which is the latest version, and built deviceQuery with Xcode 8.2. When I run it, I get:

CUDA Driver Version / Runtime Version          9.0 / 0.0
cudaGetDeviceCount returned 38
-> no CUDA-capable device is detected
Result = FAIL

This device should definitely be CUDA-capable, so I’m not sure where to proceed from here.

Stumped on this one. The GPU is definitely detected by the OS and the Nvidia prefpanes know it’s there. But is not available for CUDA.