38
Chapter 3: Maintenance and Component Installation
DIMM Population Requirements for CPUs
For optimal memory performance, follow the tables below when populating memory modules.
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), 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)
General Population Requirements
DIMM Mixing Rules
•
Please populate all memory modules with DDR4 DIMMs only.
•
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