Apple macOS 10.15 vs. Windows 10 vs. Ubuntu 19.10 Performance Benchmarks
First up was Valve's Dota 2 game that runs well across Windows/Linux/macOS. With Dota 2 using the OpenGL renderer, both Ubuntu 19.10 and Windows 10 were much faster than macOS 10.15. No surprise really considering Apple has deprecated OpenGL on macOS in favor of their own Metal graphics API.
When running Dota 2 with Vulkan, the performance was now similar across all three platforms. It's worth noting the macOS 10.15 performance was much better with Vulkan -- which Valve is achieving through the use of MoltenVK to map to the Metal drivers. Windows did still have a slight lead, but for all key purposes the performance was similar.
When running Xonotic that is OpenGL rendered and has similar quality builds across all three operating systems, Windows 10 was delivering much better performance with the Radeon Pro 450 than under Ubuntu 19.10 with its default drivers and macOS 10.15 with their lousy OpenGL driver coverage.