Owners Manual

Table 28. Memory populations and operating frequencies (continued)
DIMM Type
DIMMs Populated/
Channel
Voltage
Operating Frequency
(in MT/s)
Maximum DIMM
Rank/Channel
2
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 installing memory modules:
● x4 and x8 DRAM based DIMMs can be mixed. For more information, see the Mode specific guidelines section.
● Up to two dual- or single-rank RDIMMs can be populated per channel.
● Populate DIMM sockets only if a processor is installed. For single-processor systems, sockets A1 to A8 are available. For
dual-processor systems, sockets A1 to A8 and sockets B1 to B8 are available.
● Populate all sockets with white release levers first, and then all the sockets with black release levers.
● 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 levers
and 4 GB DIMMs in the sockets with black release levers.
● In a dual-processor configuration, the memory configuration for each processor should be identical through the first eight
slots. 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 two DIMMs per processor (one DIMM per channel) at a time to maximize performance.
Related references
Mode-specific guidelines on page 63
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 need Advanced ECC mode to gain SDDC.
Advanced Error Correction Code
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.
Memory optimized independent channel mode
This mode supports Single Device Data Correction (SDDC) only for memory modules that use x4 device width. It does not
impose any specific slot population requirements.
Memory sparing
NOTE: To use memory sparing, this feature must be enabled in System Setup.
Installing and removing system components 63