Radeon vs. NVIDIA With Windows 10 & Ubuntu Linux
First up are some of the OpenGL tests where they aren't "ports" to Linux but natively supported well across both operating systems. They also tend to be open-source titles. This is mainly for getting a look at the overall performance of the drivers before getting to the more interesting games that tend to be ports to Linux.
NVIDIA on both Windows and Linux was much faster with the GTX 1060 than the RX 580 and the GTX 1080 over the RX Vega 64 for this very basic GL2 game. Though note the Radeon Linux driver here was ~44% faster than Windows while the NVIDIA Linux driver is only 24~27% faster than the Windows performance.
With the Unigine Heaven benchmark, the performance for both NVIDIA and AMD is very close between Windows 10 and Ubuntu Linux.
NVIDIA's Unigine Valley performance was also very close between operating systems while the Radeon performance was slightly lower on Linux.
Xonotic on Linux was faster with the Radeon graphics cards while under Windows the NVIDIA driver was much faster.