5
5 DIMM Population Guidelines for Optimal Performance
For optimal memory performance, follow the instructions listed in the tables below when
populating memory modules.
5.1
Key Parameters for DIMM Confi guration
Key Parameters for DIMM Confi gurations
Parameters
Possible Values
Number of Channels
1, 2, 3, 4, 5, or 6
Number of DIMMs per Channel
1DPC (1 DIMM Per Channel) or 2DPC (2 DIMMs Per Channel)
DIMM Type
RDIMM (w/ECC), 3DS RDIMM, LRDIMM, 3DS LRDIMM
DIMM Construction
•
non-3DS RDIMM Raw Cards: A/B (2Rx4), C (1Rx4), D (1Rx8), E (2Rx8)
•
3DS RDIMM Raw Cards: A/B (4Rx4)
•
non-3DS LRDIMM Raw Cards: D/E (4Rx4)
•
3DS LRDIMM Raw Cards: A/B (8Rx4)
5.2
DIMM Mixing Guidelines
General DIMM Mixing Guidelines
DIMM Mixing Rules
•
All DIMMs must be all DDR4 DIMMs.
•
x4 and x8 DIMMs can be mixed in the same channel.
•
Mixing of LRDIMMs and RDIMMs is not allowed in the same channel, across different
channels, and across different sockets.
•
Mixing of non-3DS and 3DS LRDIMM is not allowed in the same channel, across
different channels, and across different sockets.
Mixing of DIMM Types within a Channel
DIMM Types
RDIMM
LRDIMM
3DS LRDIMM
RDIMM
Allowed
Not Allowed
Not Allowed
LRDIMM
Not Allowed
Allowed
Not Allowed
3DS LRDIMM
Not Allowed
Not Allowed
Allowed
DIMM Population Guidelines
3. Populating memory slots with a pair of DIMM modules of the same type and size will
result in interleaved memory, which will improve memory performance.
