9-40 Upgrading Your ServerMemory sparingMemory sparing is a feature whereby channel 2 of the memory controller in each CPU is designatedas a "spare" channel and the DIMMs (memories) that use that channel are put on standby so thatoperations can be automatically switched to a standby DIMM if a correctable error occurs in one ofthe DIMMs operating under the control of the memory controller, allowing processing to continueunimpeded.IMPORTANT: The memory sparing feature is not supported by theN8100-1644F/1650F. Additional memory sticks (N8102-371/372/373/374/375) arerequired to use the memory sparing feature. The capacity of the additional memory sticks must match thecapacity of the other memory sticks used in the server.Example: Memory sparing in a 2-CPU configurationMemory controllerMemory controllerCPU1CPU2CH0 CH1 CH2CH0 CH1 CH2Spare set #3Spare set #1Spare set #4Spare set #2CPU1-DIMM 4 CPU1-DIMM 5 CPU1-DIMM 6CPU1-DIMM 1 CPU1-DIMM 2 CPU1-DIMM 3CPU2-DIMM 4 CPU2-DIMM 5 CPU2-DIMM 6CPU2-DIMM 1 CPU2-DIMM 2 CPU2-DIMM 3Operating On standby (spare)Operating On standby (spare)NOTE: The capacity of the DIMMs recognized by the operatingsystem is less than the DIMMs' physical capacity. The capacityrecognized by the operating system depends on the number of memorysticks inserted and the capacity of each stick.
