@mrshenli and @ptrblck
If NCCL is supported only in Linux and DDP uses NCCL, how would the support in Windows actually work?  For example, I was training a network using detectron2 1 and it looks like the parallelization built in uses DDP and only works in Linux.
How would the upcoming support of DDP in Windows work (unless I’m mistaken it would likely not use NCCL)?  Would the speeds be slower as compared to doing the same training on Linux?
Finally, how would using WSL2 compare to the native Windows support of DDP?