Initially installing a DIMM

The blade server has a total of 16 direct inline memory module (DIMM) slots. The blade server supports very low profile (VLP) DDR3 DIMMs with error code correction (ECC) in 2 GB, 4 GB, 8 GB, 16 GB, and 32 GB capacities.

For a current list of supported DIMMs for the blade server, see thehttp://www.ibm.com/ servers/eserver/serverproven/compat/us/.

Depending on the memory mode that is set in the Setup utility, the blade server can support a minimum of 4 GB and a maximum of 256 GB of system memory on the system board in a blade server with one processor. If two microprocessors are installed, the blade server can support a minimum of 8 GB and a maximum of 512 GB of system memory.

Memory must be installed in pairs of DIMMs per processor installed. DIMMs must be the same size, speed, and technology within installed pairs.

If a single processor is installed, it can access the first eight DIMM slots. The following table lists the memory configurations and installation order for the BladeCenter HX5 when one processor is installed.

Table 1. System memory configuration for a single processor **(1 microprocessor)**
Installed memory	DIMM socket
Installed memory	1	2	3	4	5	6	7	8
2 DIMMs	X			X
4 DIMMs	X			X	X			X
6 DIMMs	X	X	X	X	X			X
8 DIMMs	X	X	X	X	X	X	X	X

The following table lists the memory configurations and installation order for the BladeCenter HX5 when two processors are installed.

Table 2. System memory configuration for a two processors **(2 microprocessors)**
Installed memory	DIMM socket
Installed memory	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
2 DIMMs	X			X
4 DIMMs	X			X					X			X
6 DIMMs	X			X	X			X	X			X
8 DIMMs	X			X	X			X	X			X	X			X
10 DIMMs	X	X	X	X	X			X	X			X	X			X
12 DIMMs	X	X	X	X	X			X	X	X	X	X	X			X
14 DIMMs	X	X	X	X	X	X	X	X	X	X	X	X	X			X
16 DIMMs	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X

Important: If you are installing memory in a scalable blade complex, you should install the DIMMs to have a balance of memory among processors. Additional memory can be installed in the top-most BladeCenter HX5 of the scalable blade complex blade server so that you do not need to disassemble the scalable blade complex. For example, if you are installing four DIMMs in a scalable blade complex consisting of two BladeCenter HX5 blade servers, you would install two DIMMs (in sockets 1 and 4) of each blade server.

The BladeCenter HX5 blade server supports memory mirroring. When enabled, the first DIMM quadrant is duplicated onto the second DIMM quadrant for each processor.

Note:

To enable memory mirroring, the DIMMs installed for each processor must be identical.
Memory mirroring reduces the available memory by half. For example, if the server has 64 GB of installed memory, only 32 GB of addressable memory is available when memory mirroring is enabled.

If one processor is installed, memory mirroring is set up as follows:

Table 3. Memory mirroring with one processor
DIMM Quadrant	Mirrored Quadrant
DIMM 1, DIMM 2, DIMM 3, DIMM 4	DIMM 5, DIMM 6, DIMM 7, DIMM 8

If two processors are installed, memory mirroring is set up as follows:

Table 4. Memory mirroring with two processors
DIMM Quadrant	Mirrored Quadrant
DIMM 1, DIMM 2, DIMM 3, DIMM 4	DIMM 5, DIMM 6, DIMM 7, DIMM 8
DIMM 9, DIMM 10, DIMM 11, DIMM 12	DIMM 13, DIMM 14, DIMM 15, DIMM 16

The BladeCenter HX5 blade server also supports memory sparing, in which the contents of the failing DIMM are transferred to the spare DIMM.

Note:

To enable memory sparing, the DIMMs installed for each processor must be identical.
Memory sparing reserves memory capacity for failover in the event of a DIMM failure, and the reserved capacity is subtracted from the total available memory. Memory sparing provides less redundancy than memory mirroring does. If a predetermined threshold of correctable errors is reached, the contents of the failing DIMM are copied to the spare memory, and the failing DIMM or rank is disabled. To enable memory sparing through the Setup utility, select System Settings > Memory.
See Installing a DIMM - IBM MAX5 for more information about memory requirements for the IBM MAX5 expansion blade.

If one processor is installed, memory sparing is set up as follows:

Table 5. Memory sparing with one processor
DIMM Pair	Spare Pair
DIMM 2, DIMM 3	DIMM 1, DIMM 4
DIMM 6, DIMM 7	DIMM 5, DIMM 8

If two processors are installed, memory sparing is set up as follows:

To install a DIMM, complete the following steps:

Table 6. Memory sparing with two processors
DIMM Pair	Spare Pair
DIMM 2, DIMM 3	DIMM 1, DIMM 4
DIMM 6, DIMM 7	DIMM 5, DIMM 8
DIMM 10, DIMM 11	DIMM 9, DIMM 12
DIMM 14, DIMM 15	DIMM 13, DIMM 16

Note: If all DIMMs are of the same size, the memory reference code (MRC) sets sparing in the farthest DIMM pair. Otherwise, the largest DIMM pair is set aside as spare.

To install a DIMM, complete the following steps:

Before you begin, read Safety and Installation guidelines.
Locate the DIMM connectors (see Blade server connectors - BladeCenter HX5). Determine the DIMM connector into which you will be installing memory.
If another memory module is already installed in the DIMM connector, remove it (see Removing a DIMM - BladeCenter HX5).
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.
To install the DIMMs, repeat the following steps for each DIMM that you install:
1. Make sure that both retaining clips on the DIMM connector into which you are installing the DIMM, are in the open position.
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.

Installing a DIMM - BladeCenter HX5