v The DIMM options that are available for the server are 1 GB, 2 GB, 4 GB, and 8
GB (when available). The sever supports a minimum of 1 GB and a maximum of
128 GB of system memory.
Note:
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.
v A minimum of one DIMM must be installed for each microprocessor. For
example, you must install a minimum of two DIMMs if the server has two
microprocessors installed. However, to improve system performance, install a
minimum of three DIMMs for each microprocessor.
v The maximum operating speed of the server is determined by the slowest DIMM
installed in the server.
DIMM installation sequence
v The server comes with a minimum of two 1 GB DIMMs, installed in connectors 3
and 6. When you install additional DIMMs, install them in the order shown in the
following table to optimize system performance. In non-mirroring mode, all three
channels on the memory interface for each microprocessor can be populated in
any order and have no matching requirements.
Table 7. Non-mirroring (normal) mode DIMM installation sequence
Installed microprocessors DIMM connector population sequence
Microprocessor socket 1 3, 6, 8, 2, 5, 7, 1, 4
Microprocessor socket 2 11, 14, 16, 10, 13, 15, 9, 12
Memory mirroring
v The server supports memory mirroring (mirroring mode):
– Memory-mirroring mode replicates and stores data on two pairs of DIMMs
within two channels simultaneously. If a failure occurs, the memory controller
switches from the primary pair of memory DIMMs to the backup pair of
DIMMs. To enable memory mirroring through the Setup utility, select System
Settings → Memory. When you use the memory mirroring feature, consider
the following information:
- When you use memory mirroring, you must install a pair of DIMMs at a
time. One DIMM must be in channel 0, and the mirroring DIMM must be in
the same slot in channel 1. The two DIMMs in each pair must be identical
in size, type, and rank (single or dual) , and organization, but not in speed.
The channels run at the speed of the slowest DIMM in any of the channels.
- Channel 2, DIMM connectors 8 ,7, 15, and 16 are not used in
memory-mirroring mode.
- The maximum available memory is reduced to half of the installed memory
when memory mirroring is enabled. For example, if you install 64 GB of
memory, only 32 GB of addressable memory is available when you use
memory mirroring.
The following diagram shows the memory channel interface layout with the DIMM
installation sequence for mirroring mode. The numbers within boxes indicate the
DIMM population sequence in pairs within the channels, and the numbers next to
the boxes indicate the DIMM connectors within the channels. For example, the
following illustration shows the first pair of DIMMs (indicated by ones (1) inside
the boxes) should be installed in DIMM connectors 3 on channel 0 and DIMM
connector 6 on channel 1 DIMM connectors 7, 8, 15, and 16 on channel 2 are
60 ThinkServer RD210 Types 3795, 3796, 3818, and 3819: Installation and User Guide
