System Memory; System Memory Guidelines - Dell EMC PowerEdge R940 Installation And Service Manual

Figure 55. Cable routing – 24 x 2.5 inch hard drive backplane with NVMe cards
1. 24 x 2.5 inch hard drive backplane with expander board
3. PCIe cable (BP: BP PCIE B2, BP PCIE A2 to RAID controller)4. backplane signal cable (BP: BP SIG to MB)
5. system board
7. NVMe card (slot 8)
9. NVMe card (slot 12)
11. PCIe cable (BP: BP PCIE B0, BP PCIE A0 to RAID
controller)
13. cable management bracket (right)

System memory

System memory guidelines

The system supports DDR4 registered DIMMs (RDIMMs), load reduced DIMMs (LRDIMMs), data center persistent memory
module (PMem) and non-volatile dual in-line DIMM-Ns (NVDIMM-N). System memory holds the instructions that are executed
by the processor.
The PowerEdge R940 system (without PEM) contains 24 memory sockets split into two sets of 12 sockets, one set per
processor. Each 12-socket set is organized into six channels. Six memory channels are allocated to each processor. In each
channel, the release tabs of the first socket are marked white, and the second socket black.
The PowerEdge R940 system (with PEM) contains 48 memory sockets split into four sets of 12 sockets, one set per processor.
Each 12-socket set is organized into six channels. Six memory channels are allocated to each processor. In each channel, the
release tabs of the first socket are marked white, and the second socket black.
2. backplane power cable A (BP: BP PWR_A to MB)
6. expansion card riser (left)
8. expansion card riser (right)
10. NVMe card (slot 11)
12. PCIe cable (BP: BP PCIE B1, BP PCIE A1 to RAID controller)
14. backplane power cable B (BP: BP PWR_B to MB)
Installing and removing system components 63