Ram installation Modes

All 3 modes support ECC.  Optimizer mode allows you to use all the slots and memory capacity.

Regards,

Across the CPU channel and the CPU socket, DIMM populations can be different as long as the population rules for each socket and RAS mode are followed.

• If DIMMs of different speeds are mixed, all channels across all CPUs operate at the slowest DIMM's common frequency.
• Only one type of DIMM is allowed per system: UDIMM, RDIMM, or LRDIMMs. They cannot be mixed.
• DIMM slot latches/ejection tabs are color coded per PowerEdge Behavioral Specification to aid identification of proper DIMM placement. First DIMM is white, second DIMM is black, third DIMM is green.
• Advanced ECC (Lockstep, SDDCx8) and Mirror modes: Channels 0 and 1 and channels 2 and 3 must be identical channel level configurations. Advanced ECC with Mirroring is not supported. This is primarily due to Ivy Bridge-EP architectural limitations which do not support mirroring on channels 0/2 and 1/3.
• DIMMs must be installed in each channel starting with the DIMM farthest from the processor. DIMMs should be installed with largest rank count to smallest. For example if DR are mixed with SR DIMMs, DRs should be placed in the lowest DIMM slots, then the SR DIMMs.
• Population order will be identified by the silkscreen designator and the System Information Label (SIL) located on the chassis cover. The graphic below indicates the installation order for each configuration type. In dual CPU configurations, memory should be built out evenly: A1, B1, A2, B2, etc.
  
  • Memory Optimized (Independent): {1, 2, 3, 4}, { 5, 6, 7, 8}, {9, 10, 11, 12}
  • Advanced ECC (Lockstep / x8 SDDC) and Mirrored: {1+2, 3+4}, {5+6, 7+8}, {9+10, 11+12}
  • Selective Mirroring: TBD (post RTS feature)
  • Quad Rank or UDIMM: {1, 2, 3, 4}, {5, 6, 7, 8}

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