Personally I wouldn't put a 5800x on a 450 chipset..
I had problems with 3700x on 370 chipset, so I purchased Asus Tuf Gaming x570 mobo..
The problems I had with the 370 was VRM's were not up to powering the 3700x, you could have the same problem with the B450..
If I were you get a B550 or better an x570 mobo..
AMD Ryzen 9 9900x, Asus Prime X 9070, Asus Crosshair X870E Hero, 64gb Kingston DDR5 6000, Samsung 980pro 1tb NVME, Samsung 970 EVO Plus 1tb NVME, DeepCool Mystique 360 AIO, Antec Titanium 1000w.