Fujitsu PRIMERGY RX2540 M7 Upgrade And Maintenance Manual page 348

Main memory
Figure 209: Installing a memory dummy module - variant 2
▶ Align the notch on the bottom of the module with the crossbar in the slot.
▶ Press down on the dummy module until the securing clips snap into the
cutouts at each end of the module.
If the second CPU (CPU2) is not installed, install memory dummy
modules in memory slots corresponding to the CPU2 socket or install a
CPU dummy cover on the CPU2 socket.
If the CPU dummy cover is installed, the memory dummy modules
cannot be installed in the memory slots, as the CPU dummy cover is
installed in two memory slots located next to the socket and blocks all
the memory slots from being used. The installation of the dummy cover
on the second CPU slot allows you to avoid unexpected thermal
conditions.
348 Upgrade and Maintenance Manual RX2540 M7