10 x 2.5-inch front drive bays (6SAS/SATA + 4NVMe)
The server model is configured with one 10 x 2.5-inch AnyBay front drive backplane. Below lists all 
supported configurations with this front drive backplane.
Note: The AnyBay backplane is used as “6 SAS/SATA + 4 NVMe” backplane.
Configuration option
Rear BP
Qty. Type
Config. 1
1 2 x 2.5" SAS/SATA
Cable routing information for configuration 1
Config.
Front BP Rear BP
System board
1
NVMe 0-1
PCIe 3
NVMe 2–3
PCIe 7
SAS 0 PCIe 2
SAS 1 PCIe 4
SAS PCIe 5
86 ThinkSystem SR645 Setup Guide