Asus ESC4000 G2 - Manual (Page 68)

4-12 Chapter 4: Motherboard information
5. Serial General Purpose Input/Output connectors
(8-1 pin ISGPIO1, SGPIO1)
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 ISGPIO 1 connector is for SATA connectors—ISAS connectors.