However, I now noticed a a weird thing with the Nvidia driver in Linux Mint 20.2, even though I set the power mix mode to performance mode in the Nvidia X Server settings, after I reboot my system it reset back to adaptive mode. 45-46 fps in Linux, 38-39 fps in Windows in the same situation and settings in X-Plane 11. I went back to reinstall X-Plane 11 in Linux with the same DLC as before and I can confirm that on my system it's performing better in LInux than in Windows when using Vulkan. I currently have a dual boot system with Linux Mint 20.2 (just for X-Plane 11 usage) on my 2TB 970 EVO Plus NVMe and Windows 10 on my 2TB 980 Pro NVMe. I wonder why on my 4930k system OpenGL (with TO enabled) had about the same fps as Vulkan in X-Plane 11 at least in Windows 10, but on my 5800x system OpenGL (with TO enabled) has higher fps than Vulkan, at least in Windows 10. Also back when I was still using my 4930k system with the same GPU, at that same spot I got around 23-24 fps in both (OpenGL with TO enabled) and Vulkan, except I had scenery shadows disabled at the time. The first session was around 47 fps and the second and third session was around 46 fps so I'm going to assume the around 46 fps is the true fps of that spot in OpenGL mode with threaded optimizations enabled and currently around 38 fps in that same spot in Vulkan mode, and this is in Windows. This time it didn't drop to 36 fps on the 2nd sequential session. Update: I just sequentially ran 3 sessions of X-Plane 11 in OpenGL mode, and was around 46-47 fps at that same spot.
Could it be that threaded optimizations stopped working on the 2nd session in OpenGL? I wonder since that feature in the drivers gives me about a 20% performance boost in X-Plane 11 in OpenGL but does nothing for Vulkan mode?
So I'm not sure what the true fps in OpenGL should be on my 5800x, 36 fps or 46 fps. This strange anomaly in OpenGL mode never occurred when I was running X-Plane 11 on my i7-4930k system, which is now out of commission, but it seems to only be happening on my Ryzen 5800x system with the same GPU installed. However, something strange happens when I exit X-Plane 11 and restart X-Plane 11, next time the frame rate is around 36 fps at that same spot and this happens just in OpenGL mode.
I get around 46 fps in OpenGL (with threaded-optimizations enabled) in that exact same spot and same settings except in OpenGL mode in Windows 10. However, I tested OpenGL in X-Plane 11 in Windows and I'm getting a higher frame rate in OpenGL with threaded optimizations turned on in the drivers, at least in the first session with OpenGL mode. I haven't tested OpenGL in X-Plane 11 in Linux.