My guess is power or cooling.
Full tower Cosmos C700P case, 2x140 front fans, 1x140 rear fan, 2x 140 top fans. I9 7900x, liquid cooled, Single GTX 1080 Ti, liquid cooled. 54GB trident RGB 3200, Win 10. Have seen 183* Fahrenheit on CPU package (in Neverwinter, 4K) and 165* on GPU. Have a 1200W...