Asus RS924A-E6/RS8 - Manual (Page 63)

ASUS RS920A-E6/RS8; RS924A-E6/RS8 4-11
5. Serial General Purpose Input/Output connectors (8-1 pin SGPIO1/2,
SGPIO3/4)
These connectors are used for the SATA and SAS chip SGPIO interface that
controls the LED pattern generation, device information and general purpose
data. SGPIO1/2 connector is use for the peripherals of the PROMISE RAID
SATA LED, and SGPIO 3/4 connector is use for the peripherals of the LSI
PIKE RAID SAS LED.