Lenovo ThinkServer RD120 Hardware Maintenance Manual page 107

v When you use memory mirroring, you must install two pairs of DIMMs at a time.
The four DIMMs in each group must be identical. See Table 17 for the DIMM
connectors that are in each group.
Table 17. Memory mirroring DIMM installation sequence
Group DIMM connectors
1 1, 4, 7, and 10
2 2, 5, 8, and 11
3 3, 6, 9, and 12
Table 18. Memory mirroring DIMM functions
Group Active DIMMs
1 1, 4
2 2, 5
3 3, 6
v Several online-spare memory configurations are supported. The online-spare
DIMM pairs must be the same speed, type, and the same size as, or larger than,
the largest active DIMM pairs. Online-spare configurations are supported for each
branch. See Table 19 on page 90 and Table 20 on page 90 for the online-spare
DIMM connector assignments.
DIMM 12
Channel 3
DIMM 11
DIMM 10
Branch 1
DIMM 9
DIMM 8
Channel 2
DIMM 7
DIMM 6
Channel 1
DIMM 5
DIMM 4
Branch 0
DIMM 3
Channel 0
DIMM 2
DIMM 1
Mirroring DIMMs
7, 10
8, 11
9, 12
Chapter 4. Removing and replacing server components
89