SOYO SY-P4I845PEISA User Manual page 37

Hardware Installation
F. ATX12V Power Supply
The ATX12V power supply includes a 20-pin ATX connector that comply
with the ATX specification, Version 2.03 for M/B specification, a new 4-pin
receptacle/header combination--the +12V power connector--has been
defined. The presence of the +12V power connector indicates that a power
supply is ATX12V; the absence of the +12V power connector indicates that
a supply is ATX. Note that an ATX 12V power supply and at least 350W is
required for this mainboard.
Warning: Follow these precautions to preserve your Motherboard
from any remnant currents when connecting to ATX power supply:
Turn off the power supply and unplug the power cord of the
ATX power supply before connecting it to the ATX Power
connector.
SY-P4I845PEISA/GEISA
32
+12V Power Connector
ATX Power