This may be only manufacturing specific but MSI have said that their 300 series chipset MB may not support the new Zen2 procs due to a limitation in the BIOS rom size, the new Zen2 requires a BIOS rom larger than 16MB. Asus and the x370 hero and extreme both have 128MB ROMs so technically we should be OK but an offical word from Asus might be nice
Read the full story here on Guru3d >
https://www.guru3d.com/news_story/ryzen_zen_2_procs_incompatible_with_older_300_series_due_to_bios_l...