Planning on buying 7800X3D for MSFS? Consider the 7900X3D

Welcome to the forum.

There was a thread earlier, right after AM5 chips went to market, with performance issues on a brand new 7950X3D/4090 system with Windows preinstalled.

Long story short, after a lot of troubleshooting, a clean install of the Operating System resolved the issues.

Not saying this is your case necessarily.
However, anytime HW is upgraded significantly (CPU, board etc) a clean install is a must. Also, I would not trust a pre-installed OS, it is always better to start afresh on a new computer system.

Of course, if you performed a clean Windows install yourself on your high end system, it should not be needed.