Desktop Board Features 
23 
Fan Headers 
The function/operation of the fans is as follows: 
•  The fans are on when the board is in the ACPI S0 state. 
•  The fans are off when the computer is in the ACPI S3, S4, or S5 state. 
•  Each fan header is wired to a tachometer input. 
•  All fan headers support closed-loop fan control that can adjust the fan speed or 
switch the fan on or off as needed. 
•  All fan headers have a +12 V DC connection (up to 12 V DC when using 3-wire 
chassis fans). 
•  All fan headers are controlled by Pulse Width Modulation. 
•  The chassis fan header supports linear fan control on 3-wire fans. 
The Desktop Board has a 4-pin processor fan header and two 4-pin chassis fan 
headers compatible with 4-wire and 3-wire chassis fans. 
LAN Wake Capabilities 
 CAUTION 
For LAN wake capabilities, the 5 V standby line for the power supply must be capable 
of delivering adequate +5 V standby current.  Failure to provide adequate standby 
current when using this feature can damage the power supply. 
LAN wakeup capabilities enable remote wake-up of the computer through a network.  
The LAN subsystem monitors network traffic and upon detecting a Magic Packet* 
frame, it asserts a wake-up signal that powers up the computer. 
 
Instantly Available PC Technology 
 CAUTION 
For Instantly Available PC technology, the 5 V standby line for the power supply must 
be capable of delivering adequate +5 V standby current.  Failure to provide adequate 
standby current when using this feature can damage the power supply and/or effect 
ACPI S3 sleep state functionality. 
 
Instantly Available PC technology enables the board to enter the ACPI S3 (Suspend-to-
RAM) sleep state.  Instantly Available PC technology enables the board to enter the 
ACPI S3 (Suspend-to-RAM) sleep-state.  While in the S3 sleep-state, the computer will 
appear to be off (the power supply is off and the front panel power LED will behave as 
configured by the BIOS “S3 State Indicator” option).  When signaled by a wake-up 
device or event, the system quickly returns to its last known wake state.  When 
signaled by a wake-up device or event, the computer quickly returns to its last known 
awake state.