CalDigit RAID Card - Manual (Page 14)

14 A. MacPro
1.14 Connect SATA connector to the SATA port
Connect SATA connector to the SATA port on the mother board, and
make sure It's fully seated in the connector.
1.15 Conntect CalDigit optical SATA power cable middle connector
to MacPro optical bay ribbon cable end connector
1.16 Connect CalDigit optical SATA cable to the system drive and
connect the ribbon cable end connector back to optical bay