Cisco UCS C890 M5, Instruction Manual, Page: 46 / 191

Contents Page 48
4.3.6 DIMM Population Guidelines for Optimal Performance
For optimal memory performance, follow the instructions listed in the tables below
when populating memory modules.
4.3.6.1 Key Parameters for DIMM Configuration
Key Parameters for DIMM
Configurations
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)
4.3.6.2 DIMM Mixing Guidelines
General DIMM Mixing Guidelines
DIMM Mixing Rules
•
Mixing DIMMs with DC PMem and DDR4.
•
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 not allowed within a Channel
DIM
M
Type
s
RD
IM
M
LRDIMM 3DS LRDIMM
RDIM
M
All
ow
ed
Not Allowed Not Allowed
LRDI
MM
Not
All
ow
ed
Allowed Not Allowed
3DS
LRDI
MM
Not
All
ow
ed
Not Allowed Allowed