–
Mixing of non-3DS and 3DS LRDIMMs is not allowed per platform.
–
DIMMs with different frequencies can be mixed in the system, but lowest
frequency determines the system memory speed.
–
There should be at least one DDR4 DIMM per CPU socket (slot 1A/1G).
10.2.3
Modes of operation
10.2.3.1 DDR4 DIMM
Three different memory RAS modes are supported (Lockstep Channel mode is
not supported):
–
Independent Channel mode
–
Rank Sparing mode
–
Mirrored Channel mode
Below are the system level RAS mode combination limitations:
–
Mixing of Independent Channel mode and Lockstep Channel mode is not
allowed.
–
Mixing of Non-Mirrored and Mirrored Channel mode is not allowed.
–
Mixing of Lockstep mode and Mirrored Channel mode is not allowed.
–
Mixing of Rank Sparing mode and Mirrored Channel mode is not allowed.
Independent Channel mode with identical DIMMs
–
Same letter represents identical DIMMs (capacity, rank).
–
Use a "balanced" platform configuration:
– all available memory channels populated equally
– identical DIMMs in all locations (size/speed/rank)
–
Marked (*) quantity of DIMMs are not recommended because of unbalanced
configurations.
–
Unbalanced configurations can lead to significantly reduced bandwidth
because the system will fracture the memory space into multiple regions.
Main memory
260 Upgrade and Maintenance Manual RX2520 M5