fractal define c

Help for a 3900x/x570 build. I am upgrading from a 4930K, Noctua NH-D15 cooler, Fractal Define R6 case (huge), 16 gig ram, Asus board, 6 years old, showing some age. Random re-boots, OC failures, even though OC not turned on. Primary use will be various CAD programs, some 3D rendering (both...