The following table shows the memory populations and operating frequencies for the supported
configurations.
Table 37. Supported configurations
DIMM type
DIMMs
populated/
channel
Voltage
Operating frequency
(in MT/s)
Maximum DIMM rank/
channel
RDIMM
1
1.2 V
2400, 2133, 1866
Dual rank or single rank
2
General memory module installation guidelines
NOTE: Memory configurations that fail to observe these guidelines can prevent your system from
booting, stop responding during memory configuration, or operating with reduced memory.
The 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 installing
memory modules:
• RDIMMs and LRDIMMs must not be mixed.
• x4 and x8 DRAM based memory modules can be mixed. For more information, see the Mode-specific
guidelines section.
• 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.
• If memory modules with different speeds are installed, they will operate at the speed of the slowest
installed memory module(s) or slower depending on system DIMM configuration.
• Populate memory module 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 the sockets with white release tabs first, followed by the black release tabs, and then the
green 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 memory modules, populate
8 GB memory modules in the sockets with white release tabs and 4 GB memory modules in the
sockets with black release tabs.
• In a dual-processor configuration, the memory configuration for each processor should 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 memory module capacities in a system is not supported.
• Populate four memory modules 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.
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