Owners Manual
The system supports Flexible Memory Conguration, enabling the system to be congured and run in any valid chipset architectural
conguration. 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 Mode-specic guidelines.
• Up to two RDIMMs can be populated per channel regardless of rank count.
• Up to two LRDIMMs can be populated per channel regardless of rank count.
• If memory modules with dierent speeds are installed, they will operate at the speed of the slowest installed memory module(s) or
slower depending on the system DIMM conguration.
• 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 rst, followed by the black release tabs.
• When mixing memory modules with dierent capacities, populate the sockets with memory modules with the highest capacity rst. For
example, if you want to mix 8 GB and 16 GB memory modules, populate 16 GB memory modules in the sockets with white release tabs
and 8 GB memory modules in the sockets with black release tabs.
• In a dual-processor conguration, the memory conguration 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.
• The memory conguration 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 dierent capacities can be mixed provided other memory population rules are followed (for example, 8 GB and 16
GB memory modules can be mixed).
• Mixing of more than two memory module capacities in a system is not supported.
• Populate six memory modules per processor (one DIMM per channel) at a time to maximize performance.
NOTE: Your system was optimized for performance and Dell EMC recommends not to change memory settings.
Mode-specic guidelines
Six memory channels are allocated to each processor. The congurations allowed depend on the memory mode selected.
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
specic slot population requirements.
Memory sparing
NOTE
: To use memory sparing, this feature must be enabled in BIOS menu of System Setup.
Table 37. Memory sparing
Type Description
Memory sparing (Single Rank) Memory sparing allocates one rank per channel as a spare. If excessive correctable
errors occur in a rank or channel, they are moved to the spare area while the
operating system is running to prevent errors from causing an uncorrectable failure.
Requires population of two ranks or more per channel.
Memory sparing (Multi Rank) Memory sparing allocates two ranks per channel as a spare. If excessive
correctable errors occur in a rank or channel, they are moved to the spare area
while the operating system is running to prevent errors from causing an
uncorrectable failure. Requires population of three ranks or more per channel.
With single rank memory sparing enabled, the system memory available to the operating system is reduced by one rank per channel. For
example, in a dual-processor conguration with twenty four 16 GB dual-rank memory modules, the available system memory is: 3/4 (ranks/
72
Installing and removing system components