Table 25. Sample memory configuration
DIMM Type
DIMMs Populated/
Channel
Operating Frequency (in
MT/s)
Maximum DIMM Rank/Channel
1.2 V
RDIMM
1
2133, 1866, 1600, 1333
Dual rank or single rank
2
2133, 1866, 1600, 1333
Dual rank or single rank
3
1866, 1600, 1333
Dual rank or single rank
LRDIMM
1
2133, 1866, 1600, 1333
Quad rank
2
2133, 1866, 1600, 1333
Quad rank
3
1866, 1600, 1333
Quad rank
General memory module installation guidelines
This system supports Flexible Memory Configuration, which lets you configure the system to run in any
valid chipset architectural configuration. The following are the recommended guidelines for installing
memory modules:
• RDIMMs and LRDIMMs must not be mixed.
• x4 and x8 DRAM based DIMMs can be mixed. For more information, see
.
• Up to three dual- or single-rank RDIMMs can be populated per channel.
• Up to three LRDIMMs can be populated per channel regardless of rank count.
• 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, then black, and then green.
• Populate the sockets by highest rank count in the following order — first in sockets with white release
levers, then black, and then green. For example, if you want to mix single-rank and dual-rank DIMMs,
populate dual-rank DIMMs in the sockets with white release tabs and single-rank DIMMs in the
sockets with black release tabs.
• When mixing memory modules with different capacities, populate the sockets with memory modules
with highest capacity first. For example, if you want to mix 4 GB and 8 GB DIMMs, populate 8 GB
DIMMs in the sockets with white release tabs and 4 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 capacities can be mixed provided other memory population rules are
followed (for example, 4 GB and 8 GB memory modules can be mixed).
• Mixing of more than two DIMM capacities in a system is not supported.
• Populate four DIMMs per processor (one DIMM per channel) at a time to maximize performance.
Mode-specific guidelines
Four memory channels are allocated to each processor. The allowable configurations depend on the
memory mode selected.
NOTE: You can mix x4 and x8 DRAM based DIMMs to support RAS features. However, all guidelines
for specific RAS features must be followed. x4 DRAM based DIMMs retain Single Device Data
Correction (SDDC) in memory optimized (independent channel) mode. x8 DRAM based DIMMs
require Advanced ECC mode to gain SDDC.
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