Installing a memory module

Use these instructions to install memory modules in the blade server.

The blade server has a total of twelve direct inline memory module (DIMM) slots. The blade server supports very low profile (VLP) DDR3 single-rank, dual-rank, or quad-rank DIMMs with error code correction (ECC) in 2 GB, 4 GB, 8 GB, and 16 GB capacities. For a list of supported DIMMs for the blade server, see Parts listing.

Note

Do not mix DIMMs with different DDR3 voltages, frequencies, and ECC modes.

In BladeCenter E, not all memory option supported on HS23E are supported in all configurations. CPU throttling may occur within the BladeCenter E's ambient air temperature specification range if these limitations are not followed as below:

• DIMM:
  • IBM option part number 90Y3221 (CRU part number 90Y3223) - 16 GB 4R x 4 1066 MHz VLP RDIMM 1.35V.
• Limitation:
  • Not supported with two 95W microprocessors and two DIMMs per channel in BladeCenter E.
  • Supported with one 95W microprocessor and two DIMMs per channel (up to 6 DIMMs attached to microprocessor 1) or two 95W microprocessors with one DIMM per channel (up to 3 DIMMs attached to microprocessor 1 and 3 DIMMs attached to microprocessor 2) with DIMM fillers removed in empty DIMM connectors of microprocessor 2.

After you install or remove a DIMM, you must change and save the new configuration information by using the Setup utility. When you turn on the blade server, a message indicates that the memory configuration has changed. Start the Setup utility and select Save Settings (see Setup utility menu for more information) to save changes.

The memory is accessed internally through the system using three channels per microprocessor. Each channel contains two DIMM connectors. The following table lists each channel and which DIMM connectors belong to the channel.

Table 1. Memory channel configuration

Memory channel	DIMM connector (microprocessor 1)	DIMM connector (microprocessor 2)
Channel 1	1 and 2	7 and 8
Channel 2	3 and 4	9 and 10
Channel 3	5 and 6	11 and 12

Depending on the memory mode that is set in the Setup utility, the blade server can support a minimum of 2 GB and a maximum of 96 GB of system memory on the system board in a blade server with one microprocessor. If two microprocessors are installed, the blade server can support a minimum of 4 GB and a maximum of 192 GB of system memory. There are three different memory modes:

• Independent channel mode: Independent channel mode gives a maximum of 96 GB of usable memory with one microprocessor installed, and 192 GB of usable memory with two microprocessors installed (using 16 GB DIMMs). The DIMMs can be installed without matching sizes. See the table below for the memory installation order.

  Table 2. Independent channel mode DIMM installation sequence

  One microprocessor installed	Two microprocessors installed
  DIMM connectors 5, 3, 1, 6, 4, 2	DIMM connectors 5, 11, 3, 9, 1, 7, 6, 12, 4, 10, 2, 8

• Rank sparing mode: In rank-sparing mode, one memory DIMM rank serves as a spare of the other ranks on the same channel. The spare rank is held in reserve and is not used as active memory. The spare rank must have identical or larger memory capacity than all the other active memory ranks on the same channel. After an error threshold is surpassed, the contents of that rank is copied to the spare rank. The failed rank of memory is taken offline, and the spare rank is put online and used as active memory in place of the failed rank.
  Note

  Rank sparing mode is supported if the blade server meets one of the following memory requirements:

  • One quad-rank DIMM
  • More than one DIMM per channel
  • An even number of single-rank or dual-rank DIMMs

  For rank sparing mode memory installation order on a blade server with quad-rank DIMMs, see Independent channel mode DIMM installation sequence.

  The following tables show the order that single-rank or dual-rank DIMMs are installed to use rank sparing mode:

  Table 3. Rank sparing mode DIMM installation sequence for single-rank or dual-rank DIMMs (one microprocessor)

  DIMM pair	DIMM connector
  First	5, 6
  Second	3, 4
  Third	1, 2

  Table 4. Rank sparing mode DIMM installation sequence for single-rank or dual-rank DIMMs (two microprocessors)

  DIMM pair	DIMM connector
  First	5, 6 11, 12
  Second	3, 4
  Third	9, 10
  Fourth	1, 2
  Fifth	7, 8

  Note

  In rank sparing mode, if any of the installed DIMMs does not meet the requirements listed above, the system is executed as independent channel mode.
• Mirrored channel mode: In mirrored channel mode, memory is installed in pairs. Each DIMM in a pair must be identical in capacity, type, and rank count. The channels are grouped in pairs with each channel receiving the same data. One channel is used as a backup of the other, which provides redundancy. The memory contents on channel 2 are duplicated in channel 3. Channel 1 DIMM connectors 1, 2, 7, and 8 are not used in mirrored channel mode. The maximum available memory (with 16 GB DIMMs) is 32 GB for a single microprocessor system and 64 GB for a dual microprocessor system.
  Important

  The memory configuration of channel 2 must match that of channel 3. For example, if a 4 GB Dual Rank DIMM is installed into the DIMM connector 3 (channel 2), then a 4 GB Dual Rank DIMM must also be installed into the DIMM connector 5 (channel 3). Memory channel configuration lists each channel and which DIMM connectors belong to the channel.

  The following table shows the order that memory DIMMs are installed to use mirrored channel mode.

  Table 5. System memory configuration for mirrored channel mode (one microprocessor)

  DIMM pair	DIMM connector
  First	3 and 5
  Second	4 and 6

  Table 6. System memory configuration for mirrored channel mode (two microprocessors)

  DIMM pair	DIMM connector
  First	3 and 5, 9 and 11
  Second	4 and 6
  Third	10 and 12

Note

In mirrored channel mode, if any of the installed DIMMs does not meet the requirements listed above, the system is executed as independent channel mode.

To install a DIMM, complete the following steps:

1. Locate the DIMM connectors (see Blade server connectors). Determine which DIMM connector you will be installing memory into.
2. If a DIMM filler or another memory module is already installed in the DIMM connector, remove it (see Removing a memory module).
   Note

   A DIMM or DIMM filler must occupy each DIMM socket before the blade server is turned on.
3. Touch the static-protective package that contains the DIMM to any unpainted metal surface on the BladeCenter unit or any unpainted metal surface on any other grounded rack component in the rack in which you are installing the DIMM for at least two seconds; then, remove the DIMM from its package.
4. To install the DIMMs, repeat the following steps for each DIMM that you install:
   
   
   1. Make sure that the retaining clips are in the open position, away from the center of the DIMM connector.
   2. Turn the DIMM so that the DIMM keys align correctly with the DIMM connector on the system board.
      Attention

      To avoid breaking the retaining clips or damaging the DIMM connectors, handle the clips gently.
   3. Press the DIMM into the DIMM connector. The retaining clips will lock the DIMM into the connector.
   4. Make sure that the small tabs on the retaining clips are in the notches on the DIMM. If there is a gap between the DIMM and the retaining clips, the DIMM has not been correctly installed. Press the DIMM firmly into the connector, and then press the retaining clips toward the DIMM until the tabs are fully seated. When the DIMM is correctly installed, the retaining clips are parallel to the sides of the DIMM.
5. If the DIMM access door is open, use your fingers to close it.
6. Install the cover or the optional expansion unit onto the blade server (see Installing the blade server cover).
7. Install the blade server into the BladeCenter unit (see Installing the blade server in a BladeCenter unit).