Dell EMC PowerEdge XE7440 Installation And Service Manual

● Up to two LRDIMMs can be populated per channel regardless of rank count.● A maximum of two different ranked DIMMs can be populated in a channel regardless of rank count.● If memory modules with different speeds are installed, they will operate at the speed of the slowest installed memorymodule(s).● Populate memory module sockets only if a processor is installed.● Populate all the sockets with white release tabs first, followed by the black release tabs.● When mixing memory modules with different capacities, populate the sockets with memory modules with the highestcapacity first.NOTE: For example, if you want to mix 8 GB and 16 GB memory modules, populate 16 GB memory modules in thesockets with white release tabs and 8 GB memory modules in the sockets with black release tabs.● Memory modules of different capacities can be mixed provided other memory population rules are followed.NOTE: For example, 8 GB and 16 GB memory modules can be mixed.● In a dual-processor configuration, the memory configuration for each processor must be identical.NOTE: For example, if you populate socket A1 for processor 1, then populate socket B1 for processor 2, and so on.● Mixing of more than two memory module capacities in a system is not supported.● Unbalanced memory configurations will result in a performance loss so always populate memory channels identically withidentical DIMMs for best performance.● Populate six identical memory modules per processor (one DIMM per channel) at a time to maximize performance.Mode-specific guidelinesThe configurations allowed depend on the memory mode selected in the System BIOS.Table 10. Memory operating modesMemory Operating Mode DescriptionOptimizer Mode The Optimizer Mode if enabled, the DRAM controllersoperate independently in the 64-bit mode and provideoptimized memory performance.Mirror Mode The Mirror Mode if enabled, the system maintains twoidentical copies of data in memory, and the total availablesystem memory is one half of the total installed physicalmemory. Half of the installed memory is used to mirror theactive memory modules. This feature provides maximumreliability and enables the system to continue running evenduring a catastrophic memory failure by switching over to themirrored copy. The installation guidelines to enable MirrorMode require that the memory modules be identical in size,speed, and technology, and they must be populated in sets of6 per processor.Single Rank Spare Mode Single Rank Spare Mode allocates one rank per channel as aspare. If excessive correctable errors occur in a rank orchannel, while the operating system is running, they aremoved to the spare area to prevent errors from causing anuncorrectable failure. Requires two or more ranks to bepopulated in each channel.Multi Rank Spare Mode Multi Rank Spare Mode allocates two ranks per channel as aspare. If excessive correctable errors occur in a rank orchannel, while the operating system is running, they aremoved to the spare area to prevent errors from causing anuncorrectable failure. Requires three or more ranks to bepopulated in each channel.With single rank memory sparing enabled, the systemmemory available to the operating system is reduced by onerank per channel.112 Installing and removing system components