Online-Spare Memory - IBM System x3550 M3 Type 4254 Installation And User Manual

The following illustration shows the memory connector layout that is associated with
each microprocessor. For example, DIMM connectors 10, 11, 12, 13, 14, 15, 16, 17,
and 18 (DIMM connectors are shown underneath the boxes) are associated with
microprocessor 2 (CPU2) and DIMM connectors 1, 2, 3, 4, 5, 6, 7, 8, and 9 are
associated with microprocessor 1 (CPU1). The numbers within the boxes indicate
the installation sequence of the DIMM pairs. For example, the first DIMM pair
(indicated within the boxes by ones (1)) should be installed in DIMM connectors 1
and 2, which is associated with microprocessor 1 (CPU1).
Note: You can install DIMMs for microprocessor 2 as soon as you install
Figure 2. Memory connectors associated with each microprocessor for memory mirroring
The following table shows the installation sequence for installing DIMMs in
memory-mirroring mode:

Online-spare memory

The memory online-spare feature disables the failed memory from the system
configuration and activates an online-spare DIMM to replace the failed active DIMM.
You can enable either online-spare memory or memory mirroring in the Setup utility
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IBM System x3550 M3 Types 4254 and 7944: Installation and User's Guide
Table 9. Connectors on each memory channel
Memory channel
Channel 0
Channel 1
Channel 2
microprocessor 2; you do not have to wait until all of the DIMM slots for
microprocessor 1 are filled.
CPU2
Table 10. Memory-mirroring mode DIMM population sequence
DIMMs
First pair of DIMMs
Second pair of DIMMs
Third pair of DIMMs
Fourth pair of DIMMs
Fifth pair of DIMMs
Sixth pair of DIMMs
Note: DIMM connectors 7, 8, 9, 16, 17, and 18 are not used in memory-mirroring mode.
DIMM connectors
1, 2, 3, 10, 11, 12
4, 5, 6, 13, 14, 15
7, 8, 9, 16, 17, 18
6 5 4 6 5 4
10 11 12 13 14 15
1 2 3 1
9 8 6 5 3
7 4
Number of installed
microprocessors
1
1
1
2
2
2
16 17 18
CPU1
2 3
2 1
DIMM connector
3, 6
2, 5
1, 4
12, 15
11, 14
10, 13