Chapter 4. IBM NeXtScale nx360 M4 compute node 75
Table 4-7 Memory population table with two processors installed
Memory DIMM installation: Mirrored-channel mode
In mirrored channel mode, the channels are paired and both channels in a pair
store the same data.
As shown in Table 4-8, for each microprocessor, DIMM 1 and DIMM 2 form a
redundant pair, and DIMM 3 and DIMM 4 form the other redundant pair. Because
of the redundancy, the effective memory capacity of the compute node is half the
installed memory capacity.
The pair of DIMMs that are installed in each channel must be identical in
capacity, type, and rank count.
Table 4-8 Memory population with processor stalled: Mirrored channel mode
Table 4-9 on page 76 shows DIMM installation for memory mirroring if two
processors are installed.
Processor 1 Processor 2
Number of
DIMMs
DIMM 1 DIMM 2 DIMM 3 DIMM 4 DIMM 5 DIMM 6 DIMM 7 DIMM 8
2
x x
3
x x x
4
x x x x
5
x x x x x
6
x x x x x x
7
x x x x x x x
8
x x x x x x x x
Processor 1
Number of DIMMs DIMM 1 DIMM 2 DIMM 3 DIMM 4
2 x x
4
x x x x