Asus P7F-X SATA - Manual (Page 48)

2-30 Chapter 2: Hardware information
8. Serial General Purpose Input/Output connector (6-1 pin SGPIO1)
This connector is used for the SGPIO peripherals for the Intel Matrix RAID
SATA LED.
9. Serial port connector (10-1 pin COM2)
This connector is for a serial (COM) port. Connect the serial port module
cable to this connector, then install the module to a slot opening at the back
of the system chassis.