I recently had upgraded my CPU and motherboard from a I5 6600k and a non ryzen mother board (not sure what motherboard it is but it was msi brand) now I have a ryzen 7 1700 and a tomahawk 350B. I use to run an easy 60 fps with destiny 2 on my old PC and now with my new one it can only run around 40 fps. This may be something with the game but I don't think it is.
Specs:
Gtx 1060 6GB
Ryzen 7 1700
Tomahawk 350B
Corsair Vengeance LPX 16GB
750W super nova power supply
Specs:
Gtx 1060 6GB
Ryzen 7 1700
Tomahawk 350B
Corsair Vengeance LPX 16GB
750W super nova power supply