What is the maximum memory this motherboard supports and what types are compatible?

The ROG STRIX B450-F GAMING supports a maximum of 64GB across 4 DIMM slots using DDR4 un-buffered memory. Supported speeds include DDR4 3200(O.C.) / 3000(O.C.) / 2933(O.C.) / 2800(O.C.) / 2666 / 2400 / 2133 MHz in a dual-channel architecture. A DDR4 module is notched differently from DDR, DDR2, or DDR3 modules, so do not install any other type into the DDR4 slots. (Page ix, 1-5)