Troubleshooting Dual Monitor FPS Drop with High-End Specs in MSFS 2020

Firstly, I genuinely appreciate the technical details you've provided regarding your setup; it paints a clear picture. Running a dual-monitor setup in any simulator can be quite demanding, especially if both are at such a high resolution as 3840×2160. Now, let's delve into the probable causes and potential solutions:

1. Video Memory (VRAM): Even though you have a 12-gig Raedon card, remember that MSFS 2020, especially at high settings and resolutions, can be a real VRAM hog. When you add a second monitor, the VRAM demand increases. You might be nearing the limit of what your card can handle.

2. Resolution: If both monitors are running at 3840×2160, the GPU has to render a massive number of pixels. Consider temporarily reducing the resolution of the second monitor to see if there's an immediate improvement in FPS. If there's a considerable bump, then you've found a significant part of the issue.

3. Graphics Card Settings: Ensure that settings in the AMD software, like Super Resolution, are not causing conflicts. Also, double-check that the v-sync and anti-aliasing settings align with what you've set in the simulator.

4. Undocked Windows: If you're using the second monitor for undocked panels or views in the simulator, remember that this demands additional processing power. Perhaps try without any undocked views and check performance.

5. Optimization: While it's tempting to have everything on ultra, especially with the rig you have, sometimes it's about finding a balance. I'd suggest starting with settings at medium and then gradually increasing them while observing FPS until you find a balance of quality and performance that suits you.

6. Drivers: It's a basic recommendation, but ensure your GPU drivers are up-to-date. Manufacturers regularly release updates that can bring optimizations, especially for demanding software like MSFS 2020.

7. Background Applications: Ensure no resource-hogging applications are running in the background. Even with your impressive i9 and 32 gigs of DDR5, rogue applications can sometimes play spoilsport.

Lastly, I'd like to commend your efforts in trying to troubleshoot the issue on your own. The flight simming community is vast, and while there's a plethora of YouTube videos, sometimes a bit of personal touch and expert advice can go a long way. I hope some of these tips help you find a solution. If you could provide more details on specific in-sim settings and any other external applications you might be running, I'd be more than happy to assist further.