General memory module installation guidelines
To ensure optimal performance of your system, observe the following general guidelines when configuring your system memory. If your
system's memory configurations fail to observe these guidelines, your system might not boot, stop responding during memory
configuration, or operate with reduced memory. This section provides information on the memory population rules and about the non-
uniform memory access (NUMA) for single or dual processor system.
The memory bus may operate at speeds of 3200 MT/s, 2933 MT/s, or 2666 MT/s depending on the following factors:
•
System profile selected (for example, Performance Optimized, or Custom [can be run at high speed or lower])
•
Maximum supported DIMM speed of the processors
•
Maximum supported speed of the DIMMs
NOTE:
MT/s indicates DIMM speed in MegaTransfers per second.
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:
•
All DIMMs must be DDR4.
•
Mixing of memory module capacities in a system is not supported.
•
If memory modules with different speeds are installed, they operate at the speed of the slowest installed memory module(s).
•
Populate memory module sockets only if a processor is installed.
•
For dual-processor systems, sockets A1 to A16 and sockets B1 to B16 are available.
•
In Optimizer Mode, the DRAM controllers operate independently in the 64-bit mode and provide optimized memory performance.
Table 40. Memory population rules
Processor
Configuration
Memory population
Memory population
information
Single processor
Optimizer (Independent
channel) population order
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
14, 15, 16
Odd amount of DIMMs per
processor allowed.
Dual processor (Start with
processor1. Processor 1 and
processor 2 population
should match)
Optimizer (Independent
channel) population order
A{1}, B{1}, A{2}, B{2}, A{3}, B{3},
A{4}, B{4}, A{5}, B{5}, A{6}, B{6},
A{7}, B{7} A{8}, B{8}
Odd amount of DIMMs per
processor is allowed. DIMMs
must be populated
identically per processor.
•
Populate all the sockets with white release tabs first, followed by the 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.
•
Unbalanced or odd memory configuration results in a performance loss and system may not identify the memory modules being
installed, so always populate memory channels identically with identical electrical specification DIMMs for best performance.
•
Minimum recommended configuration is to populate four identical electrical specifications memory modules per processor. AMD
recommends limiting processors in that system to 32 cores or less.
•
Populate eight identical electrical specification memory modules per processor (one DIMM per channel) at a time to maximize
performance.
Non-uniform memory access (NUMA)
Non-uniform memory access (NUMA) is a memory design used in multi-processing, where the memory access time depends on the
memory location relative to the processor. In NUMA, a processor can access its own local memory faster than the non-local memory.
NUMA nodes per socket (NPS)
NUMA nodes per socket (NPS) is a new feature added that allows you to configure the memory NUMA domains per socket. The
configuration can consist of one whole domain (NPS1), two domains (NPS2), or four domains (NPS4). In the case of a two-socket
platform, an additional NPS profile is available to have whole system memory to be mapped as single NUMA domain (NPS0).
In the processors, each physical processor package contains multiple processor cores that are grouped together into core complexes and
core complex dies. A core complex (CCX) consists of maximum four processor cores and an L3 cache memory. A core complex die (CCD)
contains two CCXs. The physical processor package contains maximum eight core CCDs. A max CCD x CCX x Core processor will have
64 cores. The BIOS setup allows for the selection of an NPS profile based on down core profile and by processor SKU.
Installing and removing system components
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