The following table shows the memory populations and operating frequencies for the supportedconfigurations.DIMM Type DIMMs Populated/Channel Operating Frequency (inMT/s) Maximum DIMM Rank/Channel1.2 VRDIMM 1 2133, 1866, 1600, 1333 Dual rank or single rank2 2133, 1866, 1600, 1333 Dual rank or single rankGeneral memory module installation guidelinesYour system supports Flexible Memory Configuration, enabling the system to be configured and run inany valid chipset architectural configuration. The following are the recommended guidelines for installingmemory modules:• x4 and x8 DRAM based DIMMs can be mixed. For more information, see Mode-specific guidelines.• Up to two dual- or single-rank RDIMMs can be populated per channel.• Populate DIMM sockets only if a processor is installed. For single-processor systems, sockets A1 to A8are available. For dual-processor systems, sockets A1 to A8 and sockets B1 to B4 are available.• Populate all sockets with white release levers first, and then all the sockets with black release levers.• When mixing memory modules with different capacities, populate the sockets with memory moduleswith highest capacity first. For example, if you want to mix 4 GB and 8 GB DIMMs, populate 8 GBDIMMs in the sockets with white release levers and 4 GB DIMMs in the sockets with black releaselevers.• In a dual-processor configuration, the memory configuration for each processor should be identicalthrough the first eight slots. For example, if you populate socket A1 for processor 1, then populatesocket B1 for processor 2, and so on.• Memory modules of different capacities can be mixed provided other memory population rules arefollowed (for example, 4 GB and 8 GB memory modules can be mixed).• Mixing of more than two DIMM capacities in a system is not supported.• Populate two DIMMs per processor (one DIMM per channel) at a time to maximize performance.Mode-specific guidelinesFour memory channels are allocated to each processor. The allowable configurations depend on thememory mode selected.NOTE: You can mix x4 and x8 DRAM based DIMMs to support RAS features. However, all guidelinesfor specific RAS features must be followed. x4 DRAM based DIMMs retain Single Device DataCorrection (SDDC) in memory optimized (independent channel) mode. x8 DRAM based DIMMsrequire Advanced ECC mode to gain SDDC.The following sections provide additional slot population guidelines for each mode:Advanced ECC (lockstep)Advanced ECC mode extends SDDC from x4 DRAM based DIMMs to both x4 and x8 DRAMs. Thisprotects against single DRAM chip failures during normal operation.Memory installation guidelines:• Memory modules must be identical in size, speed, and technology.56
