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Installing a memory module

Use this information to install a memory module

The following notes describe the types of dual inline memory modules (DIMMs) that the server supports and other information that you must consider when you install DIMMs (see System-board internal connectors).

If you are replacing a memory module, make sure that:
  • The server supports industry-standard, 1066, 1333 and 1600 MHz, PC3-12800 (single-rank or dual-rank) double-data-rate 3 (DDR3), registered or unbuffered, synchronous dynamic random-access memory (SDRAM) dual inline memory modules (DIMMs) with error correcting code (ECC). For a list of supported options for the server, see the Lenovo ServerProven website; then, select your country and navigate to the list of options for the server.
  • The maximum amount of memory that the server supports is dependent on the type of memory that you install in the server.
  • The amount of usable memory is reduced, depending on the system configuration. A certain amount of memory must be reserved for system resources. To view the total amount of installed memory and the amount of configured memory, run the Setup utility. For additional information, see Using the Setup utility.
  • The maximum operating speed of the server is determined by the slowest DIMM in the server.
  • If you install a pair of DIMMs in DIMM connectors 1 and 3, the size and speed of the DIMMs that you install in DIMM connectors 1 and 3 must match each other. However, they do not have to be the same size and speed as the DIMMs that are installed in DIMM connectors 2 and 4.
  • You can use compatible DIMMs from various manufacturers in the same pair.
  • When you install or remove DIMMs, the server configuration information changes. When you restart the server, the system displays a message that indicates that the memory configuration has changed.
    Attention
    Static electricity that is released to internal server components when the server is powered-on might cause the server to stop, which could result in the loss of data. To avoid this potential problem, always use an electrostatic-discharge wrist strap or other grounding system when working inside the server with the power on.
  • The specifications of a DDR3 DIMM are on a label on the DIMM, in the following format.

    gggeRxff-PC3-wwwwwm-aa-bb-cc

    where:
    • ggg is the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)
    • e is the number of ranks
      • 1 = single-rank
      • 2 = dual-rank
      • 4 = quad-rank
    • ff is the device organization (bit width)
      • 4 = x4 organization (4 DQ lines per SDRAM)
      • 8 = x8 organization
      • 16 = x16 organization
    • wwwww is the DIMM bandwidth, in MBps
      • 8500 = 8.53 GBps (PC3-1066 SDRAMs, 8-byte primary data bus)
      • 10600 = 10.66 GBps (PC3-1333 SDRAMs, 8-byte primary data bus)
      • 12800 = 12.8 GBps (PC3-1600 SDRAMs, 8-byte primary data bus)
    • m is the DIMM type
      • E = Unbuffered DIMM (UDIMM) with ECC (x72-bit module data bus)
      • R = Registered DIMM (RDIMM)
      • U = Unbuffered DIMM with no ECC (x64-bit primary data bus)
    • aa is the CAS latency, in clocks at maximum operating frequency
    • bb is the JEDEC SPD Revision Encoding and Additions level
    • cc is the reference design file for the design of the DIMM
    • d is the revision number of the reference design of the DIMM
    Note
    To determine the type of a DIMM, see the label on the DIMM. The information on the label is in the format xxxxx nRxxx PC3-xxxxx-xx-xx-xxx. The numeral in the sixth numerical position indicates whether the DIMM is single-rank (n=1) or dual-rank (n=2).