8i/16i RAID/HBA adapter + onboard connectors
The following shows the cable connections for the 8 x 2.5-inch SAS/SATA + 8 x 2.5-inch NVMe configuration 
with one 8i/16i RAID/HBA adapter.
From To
Backplane 1: SAS 8i/16i RAID/HBA adapter on PCIe slot 2:
•  Gen 3: C0C1
•  Gen 4: C0
Backplane 2: NVMe 0-1, 2-3
Onboard: PCIe 1, PCIe 2
Backplane 2: NVMe 4-5, 6-7
Onboard: PCIe 3, PCIe 4
Connections between connectors: 
1  ↔  1 ,  2  ↔  2 ,  3  ↔  3 , ...  n  ↔  n
Figure 60. SAS/SATA cable routing
Figure 61. NVMe cable routing
Chapter 3. Internal cable routing 117