IBM 8038 Installation And User Manual page 41

Table 4. Rank sparing mode DIMM installation sequence for single-rank or dual-rank DIMMs
(one microprocessor)
DIMM pair
First
Second
Third
Table 5. Rank sparing mode DIMM installation sequence for single-rank or dual-rank DIMMs
(two microprocessors)
DIMM pair
First
Second
Third
Fourth
Fifth
Note: In rank sparing mode, if any of the installed DIMMs does not meet the
requirements listed above, the system is executed as independent channel mode.
v Mirrored channel mode: In mirrored channel mode, memory is installed in
pairs. Each DIMM in a pair must be identical in capacity, type, and rank count.
The channels are grouped in pairs with each channel receiving the same data.
One channel is used as a backup of the other, which provides redundancy. The
memory contents on channel 2 are duplicated in channel 3. Channel 1 DIMM
connectors 1, 2, 7, and 8 are not used in mirrored channel mode. The maximum
available memory (with 16 GB DIMMs) is 32 GB for a single microprocessor
system and 64 GB for a dual microprocessor system.
Important: The memory configuration of channel 2 must match that of channel
3. For example, if a 4 GB Dual Rank DIMM is installed into the DIMM connector
3 (channel 2), then a 4 GB Dual Rank DIMM must also be installed into the
DIMM connector 5 (channel 3). Table 2 on page 26 lists each channel and which
DIMM connectors belong to the channel.
The following table shows the order that memory DIMMs are installed to use
mirrored channel mode.
Table 6. System memory configuration for mirrored channel mode (one microprocessor)
DIMM pair
First
Second
Table 7. System memory configuration for mirrored channel mode (two microprocessors)
DIMM pair
First
Second
Third
DIMM connector
5, 6
3, 4
1, 2
DIMM connector
5, 6
11, 12
3, 4
9, 10
1, 2
7, 8
DIMM connector
3 and 5
4 and 6
DIMM connector
3 and 5, 9 and 11
4 and 6
10 and 12
Chapter 3. Installing options
27