Owners Manual

System memory
The system supports DDR4 registered DIMMs (RDIMMs) and load reduced DIMMs (LRDIMMs). System memory holds the instructions
that are executed by the processor.
NOTE: MT/s indicates DIMM speed in MegaTransfers per second.
Memory bus operating frequency can be 1866 MT/s, 2133 MT/s, or 2400 MT/s depending on the following factors:
• DIMM type (RDIMM or LRDIMM)
• Number of DIMMs populated per channel
• System profile selected (for example, Performance Optimized, Custom, or Dense Configuration Optimized)
• Maximum supported DIMM frequency of the processors
Your system contains 24 memory sockets split into two sets of 12 sockets, one set per processor. Each 12-socket set is organized into
four channels. In each channel, the release tabs of the first socket are marked white, the second socket black, and the third socket green.
Memory channels are organized as follows:
Table 19. Memory channels
Processor Channel 0 Channel 1 Channel 2 Channel 3
Processor 1 Slots A1, A5, and A9 Slots A2, A6, and A10 Slots A3, A7, and A11 Slots A4, A8, and A12
Processor
2
Slots B1, B5, and B9 Slots B2, B6, and B10 Slots B3, B7, and B11 Slots B4, B8, and B12
The following table shows the memory populations and operating frequencies for the supported configurations:
Table 20. Memory population
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 2400, 2133, 1866 Dual rank or single rank
3 1866 Dual rank or single rank
LRDIMM 1
1.2 V
2400, 2133, 1866 Quad rank
2 2400, 2133, 1866 Quad rank
3 2133, 1866 Quad rank
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.
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Installing and removing system components