Windows support?

[h-vetinari]

Hey all

Is there a fundamental reason nccl has no windows builds yet (other than no-one having had the time yet)?

I was playing around with windows builds on tensorflow - if I try to keep the changes from build.sh minimal, then windows should be built with nccl support as well. Of course, that can be toggled off in this case, but I wanted to ask the status nevertheless. :)

CC @conda-forge/nccl

[wolfv]

I checked on the NVIDIA website and there doesn't seem to be an NCCL for Windows. I think that's aimed at HPC environments?

[wolfv]

While NVIDIA doesn't seem to offer binaries, it seems that NCCL is possible to compile for Windows: https://github.com/MyCaffe/NCCL

[leofang]

I don't think the Windows support is official because it's not mentioned in the documentation or release notes. However, there seems to be some indication that it could work: NVIDIA/nccl#442 (comment). If you guys test it locally and figure out how to make it work, a contribution to the feedstock is certainly welcome.