vA minimum of two DIMMs must be installed in the memory expansion module
for each microprocessor in the host server.
vThe maximum operating speed of the memory expansion module is determined
by the slowest DIMM installed in the memory expansion module.
vThe memory expansion module does not come with any DIMMs when you
purchase it as an optional device. When you install DIMMs, install them in the
order shown in the following tables to optimize system performance.
vThe memory expansion module supports non-mirroring mode and
memory-mirroring mode through the host server.
–Non-mirroring mode. When you use the non-mirroring mode, install DIMMs
as indicated in the following table.
Table12. Non-mirroring mode DIMM population sequence for the memory expansion
module
Pairs of DIMMs DIMM connector population sequence
Pair 1 28, 29
Pair 2 9, 16
Pair 3 1, 8
Pair 4 20, 21
Pair 5 26, 31
Pair 6 11,14
Pair 7 3, 6
Pair 8 18, 23
Pair 9 27, 30
Pair 10 10, 15
Pair 11 2, 7
Pair 12 19, 22
Pair 13 25, 32
Pair 14 12, 13
Pair 15 4, 5
Pair 16 17, 24
Note: When you populate DIMMs in the memory expansion module,
populate the larger capacity DIMMs first, then the smaller capacity DIMMs.
–Memory-mirroring mode. When you use the mirroring mode feature,
consider the following information:
- Memory-mirroring mode replicates and stores data on sets of DIMMs
simultaneously.If a failure occurs, the memory controller switches from the
primary set of DIMMs to the backup set of DIMMs. Toenable memory
mirroring through the Setup utility,select System Settings →Memory. For
more information, see “Using the Setup utility” on page 96.
- DIMMs must be installed in sets of four. The DIMMs in each set must be
the same size and type. This is applicable also when the memory expansion
module is attached to a host server and the host server has an optional
memory tray installed in the server.You must install DIMMs in sets of four
DIMMs for memory-mirroring mode in each (server,memory tray, and the
memory expansion module).
Chapter2. Installing optional devices 85