Mirrored-channel mode - Flex System x220 Compute Nodemirrored-channel modememory mode

In mirrored-channel mode, the channels are paired, and both channels in a pair store the same data.

For each microprocessor, DIMM channels 2 and 3 form one redundant pair, and channel 1 is unused. Because of the redundancy, the effective memory capacity of the compute node is half the installed memory capacity.

Install DIMMs in pairs between the two channels in a pair. The DIMMs in each pair must be identical in capacity, type, and number of ranks. At least one DIMM pair must be installed for each microprocessor. Install DIMMs in the order shown in the following table.

Table 1. Mirrored-channel mode DIMM installation sequence.
The mirrored-channel mode DIMM installation sequence table is a three-column table where the rows indicate the DIMM installation sequence for mirrored-channel mode. Column 1 lists the DIMM installation order. Column 2 indicates the DIMM connectors to populate for systems with one microprocessor. Column 3 indicates the DIMM connectors to populate for systems with two microprocessors.
Installation order	DIMM connectors
Installation order	With one microprocessor	With two microprocessors
1	3 and 5	3 and 5, 8 and 10
2	4 and 6	4 and 6
3	-	7 and 9