KM400A-M2 v1.x maximum CPU and HDD supported information as below,
HDD:400G
CPU: AMD Duron 200Mhz FSB CPU - 950 AMD Duron 266Mhz FSB CPU - 1800
           AMD Morgan 200Mhz FSB CPU - 1.4G 
           AMD Athlon 200Mhz FSB CPU - 1.4G AMD Athlon 266Mhz FSB CPU - 1.4G
           AMD Palomino 266Mhz FSB CPU - 2100+ 
           AMD Athlon XP (0.18u) 266Mhz FSB CPU - 2100+ AMD Athlon XP (0.13u) 266Mhz FSB CPU - 2600+
           AMD Athlon XP (0.13u) 333Mhz FSB CPU - 3000+ AMD Sempron 333Mhz FSB CPU - 3000+