AMD AM4 Socket for 3rd/2nd/1st Gen AMD Ryzen™/2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics/Athlon™ with Radeon™ Vega Graphics Processors 
Memoria: 
2 x DIMM, Max. 64GB, DDR4 4400(O.C)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3400(O.C.)/3300(O.C.)/3200(O.C.)/3000(O.C.)/2933(O.C.)/2800(O.C.)/2666/2400/2133 MHz Un-buffered Memory 
Más info:
https://www.asus.com/latin/Motherboards-Components/Motherboards/PRIME/PRIME-B450M-K-II/techspec/