Lenovo ThinkServer RD210 Hardware Maintenance Manual page 95

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
• The server supports a maximum of 16 single-rank or dual-rank DIMMs.
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).
• The server supports three single-rank or dual-rank DIMMs per channel. The following table shows an
example of the maximum amount of memory that you can install using ranked DIMMs:
Table 8. Maximum memory installation using ranked DIMMs
Number of DIMMs
16
16
16
• 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.
• 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.
• The maximum operating speed of the server is determined by the slowest DIMM installed in the server.
• 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 9. Non-mirroring (normal) mode DIMM installation sequence
Installed microprocessors
Microprocessor socket 1
Microprocessor socket 2
• 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.
DIMM type
Single-rank DIMMs
Dual-rank DIMMs
Dual-rank DIMMs
DIMM connector population sequence
3, 6, 8, 2, 5, 7, 1, 4
11, 14, 16, 10, 13, 15, 9, 12
.
Chapter 7 Installing optional devices and replacing customer replaceable units
DIMM size
4 GB
4 GB
8 GB (if available)
Total memory
64 GB
64 GB
128 GB
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