3. COM1 connector (10-1 pin COM1)
This connector accommodates a serial port using an optional serial port
bracket. Connect the bracket cable to this connector then install the bracket
into a slot opening at the back of the system chassis.
P4S533-MX COM1 Connector
4. ATX power connectors (20-pin ATXPWR1, 4-pin ATX12V1)
These connectors connect to an ATX 12V power supply. The plugs from the
power supply are designed to fit these connectors in only one orientation. Find
the proper orientation and push down firmly until the connectors completely fit.
In addition to the 20-pin ATXPWR1 connector, this motherboard requires that
you connect the 4-pin ATX +12V power plug to provide sufficient power to the
Make sure that your ATX 12V power supply can provide 8A on the +12V lead
and at least 1A on the +5-volt standby lead (+5VSB). The minimum
recommended wattage is 230W, or 300W for a fully configured system. The
system may become unstable and may experience difficulty powering up if the
power supply is inadequate.
P4S533-MX ATX Power Connectors
ASUS P4S533-MX motherboard user guide