This cable connects the backplane to one of Dells mini mono RAID controllers on the R730xd 12 Bay chassis.
Plug one end into the backplane and then route the cable through the channel located on the right side of the server. The other end labeled PERC will terminate near the middle right side of the chassis. You will see the slot just before riser 1. Screw it down to a compatible DELL mini RAID controller.
This chip is known as an interposer. It’s essentially a bridge between the Mini Mono RAID controllers and the backplane. Without the interposer you are unable to install any of Dells mini RAID controllers. You can however install a regular PCIe card though. As I pointed out in this post, it limits you to a variation of riser 1 that has no x16 slot.
Find the interposer slot located right in front of Riser 1. This is near the top right corner of the chassis. Match up the slot and press down until you hear the interposer snap into place.
The purpose of this cable is to connect the backplane on the R640 10 bay with the following NVME controller. This enables NVME for the first 2 storage bays.
The purpose of this card is to enable NVME on both the DELL PowerEdge R640 and R740xd servers. On the R640 it installs in riser 1 and connects to the backplane with the following cable. On the R740xd they install into risers 1, 2, and 3 for up to 12 NVME bays.