Help with some harddrive cable

Got my HL15 unit, with the Set D cabling.

Apologies for the dumb question, what is the P4 meant to connect to?
I got 4 standard 7pin SATA connector (P0-P3), and a 8 pin connector (P4)? is this meant for supplying power to the SATA drives?

i want to check first before i cause any damage.


P4 is called a SAS Sideband connector. It’s optional and is used for monitoring the status of the backplane or RAID controller (not the drives). Maybe someone can give you a more complete explanation, I’ve never used it. But that is what you’d google if you want to read more.


As @DigitalGarden mentioned this cable is not needed and is for monitoring the backplane itself.

This is not something you need to connect. all you need to connect is the 8 SATA connectors for the system to function properly.

Excellent, thanks for the clarification!