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Unbuffered DIMMs (UDIMMs)

The following notes provide information that you must consider when you install UDIMMs.

  • The memory channels run at the lowest common frequency of the DIMMs installed.
  • The UDIMM options that are available for the server are 1 GB, 2 GB, 4 GB, and 8 GB (when available) DIMMs.
  • The server supports up to two single-rank or dual-rank UDIMMs per channel.
  • The following table lists the supported UDIMM population.
    Table 1. Supported UDIMM population per channel
    DIMM connectors per channelDIMMs installed in each channelDIMM typeDIMM speedRanks per DIMM (any combination)
    21Unbuffered DDR3 ECC1066, 1333, 1600Single-rank, dual-rank
    22Unbuffered DDR3 ECC1066, 1333, 1600Single-rank, dual-rank
  • The following table lists the maximum DIMM population using ranked UDIMMs.
    Table 2. Maximum memory population using ranked UDIMMs (depending on your model)
    Number of UDIMMsDIMM typeSizeTotal memory
    4Single-rank UDIMMs1 GB4 GB
    4Dual-rank UDIMMs2 GB8 GB
    4Dual-rank UDIMMs4 GB16 GB
    4Dual-rank UDIMMs8 GB32 GB
  • The following table shows the UDIMM memory population rule to optimize the system performance.
    Table 3. UDIMM population rule
    DIMM connector 1DIMM connector 2DIMM connector 3DIMM connector 4