Amazon.com: GIGABYTE B450 AORUS M (AMD Ryzen AM4/Micro ATX/M.2 Thermal Guard/HDMI/DVI/USB 3.1 Gen 2/DDR4/Motherboard) : Electronics
Dirt cheap Gigabyte B450 S2H is surprisingly capable of 3800 MHz RAM at 1900 FCLK (even official site only lists DDR4 3600 as a maximum supported frequency) : r/overclocking