Owners Manual

General memory module installation guidelines
Your system supports Flexible Memory Configuration, enabling the system to be configured and run in any valid chipset
architectural configuration. The following are the recommended guidelines for best performance:
● LRDIMMs, and RDIMMs must not be mixed.
● x4 and x8 DRAM based DIMMs can be mixed. For more information, see the Mode-specific guidelines section.
● A maximum of three single- or dual-rank RDIMMs can be populated in a channel.
● Populate DIMM sockets only if a processor is installed. For single-processor systems, sockets A1 to A12 are available. For
dual-processor systems, sockets A1 to A12 and sockets B1 to B12 are available.
● Populate all sockets with white release tabs first, black, and then green.
● Populate the sockets by highest capacity DIMM in the following order - first in sockets with white release levers and then
black. For example, if you want to mix 16 GB and 8 GB DIMMs, populate 16 GB DIMMs in the sockets with white release tabs
and 8 GB DIMMs in the sockets with black release tabs.
● In a dual-processor configuration, the memory configuration for each processor must be identical. For example, if you
populate socket A1 for processor 1, then populate socket B1 for processor 2, and so on.
● Memory modules of different sizes can be mixed provided that other memory population rules are followed (for example, 4
GB and 8 GB memory modules can be mixed).
● Depending on mode-specific guidelines, populate four DIMMs per processor (one DIMM per channel) at a time to maximize
performance. For more information, see the Mode-specific guidelines section.
Table 22. Heat sink — processor configurations
Processor
Configuration
Processor Type (in
Watts)
Heat
Sink
Width
Number of DIMMs
Maximum System
Capacity
Reliability, Availability, and
Serviceability (RAS) Features
Single processor 105 W, 120 W or 135 W 68 mm 12 12
Single processor 135 W (four cores, six
cores, or eight cores), 145
W, or 105 W (for acoustic
configuration)
104 mm 8 (Three DIMMs in channel 0
and channel 2 and one DIMM
in channel 1 and channel 3)
4 (One DIMM per channel)
NOTE: When using an 104 mm wide heat sink for a single processor, the memory module sockets A6, A8, A10, and A12 are
not available for population.
Dual processor 105 W, 120 W or 135 W 68 mm 24 24
Dual processor 135 W (four cores, six
cores, or eight cores), 145
W, or 105 W (for acoustic
configuration)
104 mm 16 (Three DIMMs in channel
0 and channel 2 and one
DIMM in channel 1 and
channel 3)
8 (One DIMM per channel)
Related references
Mode-specific guidelines on page 61
Mode-specific guidelines
Four memory channels are allocated to each processor. The allowable configurations depend on the memory mode selected.
Advanced Error Correction Code (lockstep)
Advanced Error Correction Code (ECC) mode extends SDDC from x4 DRAM based DIMMs to both x4 and x8 DRAMs. This
protects against single DRAM chip failures during normal operation.
The installation guidelines for memory modules are as follows:
● Memory modules must be identical in size, speed, and technology.
● DIMMs installed in memory sockets with white release levers must be identical and the same rule applies for sockets with
black release levers. This ensures that identical DIMMs are installed in matched pair —for example, A1 with A2, A3 with A4,
A5 with A6, and so on.
Installing and removing sled components
61