Lenovo System x3850 X6 Installation And Service Manual page 69

Table 11. DIMM population sequence with memory mirroring enabled or disabled in independent memory mode
(continued)
DIMM installation order
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Memory rank sparing in independent mode
This topic describes using the memory rank sparing feature in independent memory mode.
The server supports memory rank sparing. Memory rank sparing reserves memory capacity for failover in the
event of a DIMM failure, and the reserved capacity is subtracted from the total available memory. Memory
sparing provides less redundancy than memory mirroring does. If a predetermined threshold of correctable
errors is reached, the contents of the failing DIMM are copied to the spare memory, and the failing DIMM or
rank is disabled.
The DIMM installation order for memory rank sparing follows the independent mode (performance) or
lockstep mode (RAS) installation order based on the mode of operation selected.
To enable memory rank sparing through the Setup utility, select System Settings → Memory → Memory
Mode. For more information, see "Using the Setup utility" on page 123. For more information and notes
about installing DIMMs, see "Installing a memory module" on page 46.
The DIMM installation order for memory rank sparing follows the independent mode (performance) or
lockstep mode (RAS) installation order based on the mode of operation selected. For more information, see
"Independent memory mode" on page 53, and "Lockstep memory mode" on page 57.
Consider the following when using the memory rank sparing feature in independent memory mode:
Independent mode with memory
mirroring disabled
DIMM connector 15
DIMM connector 24
DIMM connector 19
DIMM connector 16
DIMM connector 8
DIMM connector 5
DIMM connector 2
DIMM connector 11
DIMM connector 14
DIMM connector 23
DIMM connector 20
DIMM connector 17
DIMM connector 7
DIMM connector 4
DIMM connector 3
DIMM connector 12
DIMM connector 13
DIMM connector 22
DIMM connector 21
DIMM connector 18
Independent mode with memory
mirroring enabled
DIMM connectors 8 and 20
DIMM connectors 5 and 17
DIMM connectors 2 and 14
DIMM connectors 11 and 23
DIMM connectors 7 and 21
DIMM connectors 4 and 18
DIMM connectors 3 and 13
DIMM connectors 12 and 22
.
Chapter 2 Installing optional devices
55