Dell EMC PowerEdge R940 Installation And Service Manual page 112

Figure 66. Cable routing - Four processor system
1 PEM
3 UPI cable connecting RM_UPI_C connectors on system board
and PEM
5 UPI cable connecting RM_UPI_B connectors on system board
and PEM
7 UPI cable connecting RM_UPI_D connectors on system board
and PEM
This image shows the cable routing for a two processor system.
112 Installing and removing system components
2 system board
4 UPI cable connecting RM_UPI_A connectors on system
board and PEM
6 cable connecting the J_PEM_CLK connectors on system
board and PEM