Lenovo ThinkServer TD200x Hardware Maintenance Manual page 211

enabling memory mirroring, see Using the Setup Utility. When you use the memory mirroring feature,
consider the following information:
• When you use memory mirroring, you must install a pair of DIMMs at a time. One DIMM must be in
channel 0, and the mirroring DIMM must be in the same connector in channel 1. The two DIMMs in each
pair must be identical in size, type, rank (single, dual, or quad), and organization. They do not have to
be identical in speed. The channels run at the speed of the slowest DIMM in any of the channels. See
Memory-mirroring mode DIMM population sequence for the DIMM connectors that are in each pair.
• Channel 2, DIMM connectors 7, 8, 15, and 16 are not used in memory-mirroring mode.
• The maximum available memory is reduced to half of the installed memory when memory mirroring is
enabled. For example, if you install 64 GB of memory, only 32 GB of addressable memory is available
when you use memory mirroring.
The following illustration shows the memory channel interface layout with the DIMM installation sequence
for mirroring mode. The numbers within the boxes indicate the DIMM population sequence in pairs within
the channels, and the numbers next to the boxes indicate the DIMM connectors within the channels. For
example, the following illustration shows that the first pair of DIMMs (indicated by ones (1) inside the
boxes) should be installed in DIMM connector 3 on channel 0 and DIMM connector 6 on channel 1. DIMM
connectors 7, 8, 15, and 16 on channel 2 are not used in memory-mirroring mode.
Figure 1. Memory channel interface layout
1
CPU 1
2
CPU 2
3
QPI
The following table lists the DIMM connectors on each memory channel.
Table 12. Connectors on each memory channel
Memory channel
Channel 0
Channel 1
Channel 2 (not used in memory mirroring)
The following illustration shows the memory connector layout that is associated with each microprocessor.
For example, DIMM connectors 9, 10, 11, 12, 13, 14, 15, and 16 (DIMM connectors are shown underneath
the boxes) are associated with microprocessor 2 socket (CPU2) and DIMM connectors 1, 2, 3, 4, 5, 6, 7,
DIMM connectors
1, 2, 3, 9, 10, 11
4, 5, 6, 12, 13, 14
7, 8, 15, 16
.
Chapter 7 Installing optional devices and replacing customer replaceable units
203