Memory mirroring

In the mirrored-channel mode, the channels are paired, and both channels in a pair store the same data. Memory-mirroring replicates and stores data on DIMMs across two or four channels simultaneously. If a failure occurs, the memory controller switches from the DIMMs on the primary channel to the DIMMs on the backup channel. To enable memory mirroring through the Setup utility, select System Settings → Memory → Memory Mode.

For more information, see Using the Setup utility.

When you use the memory mirroring mode, consider the following information:

• The server supports single-socket memory mirroring. Memory channel 0 mirrors channel 1, and memory channel 2 mirrors channel 3. This mirroring provides redundancy in memory but reduces the total memory capacity in half.
• DIMMs must be installed in pairs for each microprocessor when using the memory mirroring feature.
• The DIMM population must be identical for memory channel 0 and memory channel 1, and identical for memory channel 2 and memory channel 3.
• Memory mirroring reduces the maximum available memory by half of the installed memory. For example, if the server has 64 GB of installed memory, only 32 GB of addressable memory is available when memory mirroring is enabled.

The following table lists the DIMM installation sequence for the memory-mirroring mode.