Lenovo ThinkSystem SR635 V3 - Page 269

Figure 194. Cable routing for 8 x 2.5-inch front SAS/SATA drive bays with an 8i or 16i SFF RAID adapter (Gen 4)
Table 35. Mapping between one 8 x 2.5-inch front SAS/SATA backplane and an SFF HBA/RAID adapter
From To
1 SAS 0 and SAS 1 on the front backplane 1 C0 on the SFF HBA/RAID adapter
Chapter 6. Internal cable routing 259