Starting from PCB version 2.0, The A7N8X motherboard supports Front Side Bus(FSB) 400. The users of PCB 1.06 or earlier version can update their motherboard BIOS to get FSB 400 support. The PCB (Printed Circuit Board) version is located beside the motherboard name printed on the motherboard. PCB 2.0 BIOS version or later are not compatible with PCB 1.06 or earlier BIOS versions