AMD Ryzen 5000 Zen 3 support is rolling out for ASUS, ASRock, Biostar, Gigabyte and MSI 500 series motherboards; no B450 or X470 support until January 2021 at the earliest - NotebookCheck.net News
B450 or B550 for Ryzen 5000 Series? Should B450 Owners Upgrade? - YouTube
GIGABYTE's x470 and B450 motherboards now support Ryzen 5000 CPUs