Fujitsu PRIMERGY RX2540 M4, Upgrade And Maintenance Manual, Page: 330 / 639

330 Upgrade and Maintenance Manual
RX2540 M4
Main memory
10.1.1 Population rules
– Non-ECC DIMMs are not supported on this platform.
– x4 and x8 DIMMs cannot be mixed in the same channel.
– Mixing of LRDIMM with RDIMM type is not allowed per platform.
– Mixing of non-3DS and 3DS LRDIMMs is not allowed per platform.
– DIMMs with different frequencies can be mixed in the system.
– Lowest frequency determines the system memory speed.
– There should be at least one DDR4 DIMM per CPU socket (slot 1A/1G).
– If two DIMMs with different capacity are installed in one channel, the DIMM
with the higher capacity has to be placed in slot 1 of a channel, e.g. 1A, 1B.
– If DIMMs with different ranks are installed in one channel, the DIMM with the
higher rank has to be placed in slot 1 of a channel, e.g. 1A, 1B.
– If DIMMs with different ranks are installed on one CPU socket, follow
memory module population order.
Figure 222: Mixing of DIMM types within a channel
Memory module population order DDR4 only
– If two DIMMs with different capacity are installed in one channel, the one
with the higher capacity has to be placed in slot 1 of a channel, e.g. 1A, 1B.
DIMM types RDIMM 3DS RDIMM LRDIMM 3DS LRDIMM
RDIMM allowed not allowed not allowed not allowed
3DS RDIMMs not allowed allowed not allowed not allowed
LRDIMM
not allowed not allowed allowed not allowed
3DS LRDIMM not allowed not allowed not allowed allowed