PRIME B840-PLUS WIFI-CSM. ASUS Prime series motherboards are expertly engineered to unleash the full potential of AMD Ryzen 9000 series processors. The PRIME B840-PLUS WIFI-CSM motherboard provides users and PC DIY builders with a range of performance optimizations via intuitive software and firmware features. It s designed to be Advanced AI PC-ready, offering the power and connectivity needed for demanding AI applications