Asus RS926-E7/RS8 - Manual (Page 66)

4-12 Chapter 4: Motherboard information
7. Serial General Purpose Input/Output connectors
(6-1 pin SGPIO1, 8-1 pin PSGPIO 1/2 and ISGPIO1)
The SGPIO 1 connectors are used for the Intel Rapid Storage Technology
Enterprise SGPIO interface that controls the LED pattern generation, device
information and general purpose data.
The PSGPIO 1/2 connectors are used for PIKE card.
The ISGPIO 1 connector is for SATA connectors—ISAS connectors.