Memory Mirrored Channel - Lenovo System x3650 M4 Installation And Service Manual

Table 11. Normal mode DIMM installation sequence
Number of installed
microprocessor
One microprocessor installed
Two microprocessors installed
For optimal performance:
Make sure all four memory channels of each microprocessor are populated. Each memory channels should
be populated with the same type and amount of memory per channel. Each microprocessor socket should
be populated with the same type and amount of memory per socket. 1DPC (one DIMM per channel) or
2DPC (two DIMM per channel) memory configuration are recommended. Unless there is a need for memory
capacity over memory frequency, 3DPC (three DIMMs per channel) configuration is not recommended since
3DPC configuration forces the memory subsystem to run at a lower frequency (1066MHz).
Flash DIMM installation sequence
1. When you install 2 DIMMs per channel as the following installation sequence, the memory runs at
1600 MHz.
Table 12. Flash DIMM installation sequence
DIMM type
Flash DIMM
RDIMM
2. When you install 2 DIMMs (1 Flash DIMM and 1 RDIMM) per channel as the following installation
sequence, the memory runs at 1333 MHz.
Table 13. Flash DIMM installation sequence
DIMM type
Flash DIMM
RDIMM
3. When you install 3 DIMMs (1 Flash DIMM and 2 RDIMMs) per channel as the following installation
sequence, the memory runs at 1066 MHz.
Table 14. Flash DIMM installation sequence
DIMM type
Flash DIMM
RDIMM
Please refer to the Understanding and Optimizing Memory Performance for Intel Xeon Processor E5-2600
Series in IBM Flex System, System x, and BladeCenter Platforms white paper for the detail.

Memory mirrored channel

Memory mirrored channel mode replicates and stores data on two pairs of DIMMs within two channels
simultaneously.
If a failure occurs, the memory controller switches from the primary pair of memory DIMMs to the backup
pair of DIMMs. To enable memory mirrored channel through the Setup utility, select System Settings ➙
DIMM connector population sequence
1, 4, 9, 12, 2, 5, 8, 11, 3, 6, 7, 10
1, 13, 4, 16, 9, 21, 12, 24, 2, 14, 5, 17, 8, 20, 11, 23, 3, 15, 6, 18, 7, 19, 10, 22
DIMM connector population sequence
5, 8, 17, 20
1, 4, 9, 12. 13, 16, 21, 24
DIMM connector population sequence
2, 5, 8, 11. 14, 17, 20, 23
1, 4, 9, 12. 13, 16, 21, 24
DIMM connector population sequence
3, 6, 7, 10. 15, 18, 19, 22
1, 2, 4, 5, 8, 9, 11, 12, 13, 14, 16, 17, 20, 21, 23, 24
.
Chapter 2 Installing optional devices
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