Quoting the article: “Why an external monitor? While both macOS and Windows can "loopback" frames rendered by the eGPU over the cable and onto the computer's b

Quoting the article: “Why an external monitor? While both macOS and Windows can "loopback" frames rendered by the eGPU over the cable and onto the computer's built-in monitor, operating system support for this is very recent and it introduces a nonzero bandwidth cost which can result in lower framerates as well as frames being dropped.”