I just upgraded from an Intel 8086k on an AORUS motherboard to a 5800x3D on a b550 AORUS and the results were nothing short of spectacular.
I was able to reuse the PSU, RAM (3200 MHz DDR4), graphics card (GTX 1080 stock), case & storage drives so, ultimately it was just a MB/CPU change. Reinstalled all the same software - no tweaks - immediately had 60 FPS (monitor refresh rate) and was buttery smooth in PMDG's 747-400 at payware airports including Aerosoft's Heathrow with heavy clouds (using the same mid to high settings as before). As close as I can get to an apples to apples comparison. Similar result with MSFS.
Best simple upgrade I've ever done.