Just thought people might be interested in this.
MacOS High Sierra comes with official support for external GPUs over Thunderbolt on any modern Mac laptop or desktop.
The built-in drivers only support AMD chipsets, but Nvidia has made MacOS support via eGPUs a priority and Nvidia Pascal drivers are available and the CUDA drivers necessary to use the CUDA Toolkit.
While it isn’t that much more expensive to just buy a PC and stick Linux on it, it may be worth it for anyone who wants to work in MacOS, wants portability or works with other GPU-intensive software like Adobe Premiere.
The affordable GTX 1080ti isn’t going to be anywhere as fast as the Tesla V100s that Amazon has on their P3 instances, but it may make sense for some people.