[PERFORMANCE FIXED]
Hey everyone, I wanted to post a few fixes that have been previously suggested so you can have them all in one place. This is mainly for those of you who have been having a rough time with underutilized high-performance hardware. I implemented all of these fixes on my machine, and I am happy to report that the difference is night and day! I can now fly the G1000 C172 in the Los Angeles Photogrammetry area at 1,500ft in full-on thunderstorms with graphics settings even higher than the “Ultra” preset without a single stutter or CTD. Before I made these changes, I couldn’t even fly at that altitude in the same area on “high” graphics preset with clear skies. I am not sure which one of these changes made the difference or if they all contributed, since I didn’t test them independently. All I know is that Mainthread isn’t redlining anymore at all, even under the highest possible workload.
All 16 logical CPU cores are also running at much higher capacity, as is my GPU. Prior to making these changes, my GPU was only at 4-5% utilization…It now runs between 50-70%. 
Anyway, I know these fixes have already been posted in various places around the forum, but I’m posting them all in the same place with a bit more of an explanation and some additional resources in hopes that it might help some of you get more out of the Sim.
1.) Disable Windows Dynamic Thread Boosting on FlightSimulator.exe using Process Lasso
https://www.reddit.com/r/flightsim/comments/ifle4x/huge_performance_booststutter_reduction_by/ NOTE: if you purchased FS2020 from the Microsoft Store or XBox App & Windows is denying you access to the WindowsApps folder, here’s how to gain access:
https://helpdeskgeek.com/windows-10/how-to-access-the-windowsapps-folder-in-windows-10/
2.) The second fix has already been posted several times, so I’ll just refer you to an earlier post by @sneaky74 : Performance Degradation with 1.14.5.0. Upgrade - #980 by sneaky74
EDIT:
3.) There is a THIRD fix that I forgot to list! Make sure Hardware-accelarated GPU scheduling is turned ON! For Win10 users, type ‘graphics settings’ in the windows search bar, open it, and flip the Hardware-accelerated GPU scheduling switch to the on position. You’ll have to reboot your PC for this change to take effect.
I hope this is able to help some of you who have been having the same issues I had 
Specs:
Settings: “Ultra”, 1080p w/ 120% render scaling & object LOD @ 200
Proc: Intel i9 9900K (4.9GHz OC)
RAM: 32GB DDR4 @ 3200MHz
GPU: MSI RTX 3070 8GB GDDR6 (Core OC +171MHz, Mem OC +1186MHz)
Hard drive: 1TB M.2 NVME SSD
OS: Windows 10 Home Edition