Modes Of Operation; Ddr4 Dimm - Fujitsu PRIMERGY CX2550 M6 Upgrade And Maintenance Manual

7.2.3

Modes of operation

7.2.3.1

DDR4 DIMM

– Unbalanced configurations can lead to significantly reduced bandwidth
because the system will fracture the memory space into multiple regions
– If two DIMM with different capacity are installed in one channel, the one with
higher capacity has to be placed in slot 1 of a channel. E.g. 1A, 1B, ...
– Rank sparing mode is not supported.
Normal mode (CX2550 M6 / CX2560 M6)
– Normal mode requires 1, 2, 4, 6 or 8 memory modules per CPU for
CX2550 M6.
– Normal mode requires 1, 2, 4, 6, 8, 12 memory modules per CPU for
CX2560 M6.
– ADDDC Sparing is available in case system configured by DDR4 xR x4
DIMM only.
– All channels must run at the same interface frequency but individual
channels may run at different DIMM timings (RAS latency, CAS latency, and
so forth).
Upgrade and Maintenance Manual
Main memory
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