2.5-inch SAS/SATA/NVMe and NVMe 8-bay backplane
Figure 16. 2.5-inch SAS/SATA/NVMe and NVMe 8-bay 
backplane connectors
1  NVMe 6-7 connector
2  NVMe 4-5 connector
3  SAS/SATA connector
4  Power connector
5  NVMe 2-3 connector
6  NVMe 0-1 connector
3.5-inch drive backplanes
Use this information to locate the connectors on the 3.5-inch drive backplanes.
3.5-inch SAS/SATA 4-bay backplane
Figure 17. 3.5-inch SAS/SATA 4-bay backplane 
connectors
1  Power connector
2  SAS/SATA connector
40 ThinkSystem ST650 V2 Maintenance Manual