Yesterday on Twitter, noted independent open source developer DontStealMacOSY released his own XG_Mobile_Station documentation on GitHub. The documentation includes a detailed run-through of how he reverse-engineered Asus' XG Mobile connector to create an open-source GPU docking station for Asus ROG Ally and ROG Flow—or as a drop-in upgrade for the original XG Station Pro, which didn't have an XG port.
Among eGPU docking solutions, there is an understood pecking order at which basic USB plummets to the bottom, and solutions like the high-bandwidth, low-latency OCuLink dominate over even Thunderbolt— but proprietary solutions like Asus' XG Mobile interface also tend to be quite performant. With some devices, eGPUs are best used (or only used) with those proprietary solutions. In the case of the two recent Asus devices this is targeted at, the ROG Ally and the ROG Flow, it's worth noting that neither device supports the faster OCuLink connector (~16 GB/s) but does support the proprietary XG connector (~8 GB/s), which approximates PCIe Gen 3 at x8 lanes for ROG Flow and just x4 lanes for ROG Ally.
