Lenovo x3650 M4 BD 5466 Installation And Service Manual page 70

• 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.
• The server supports only industry-standard double-data-rate 3 (DDR3) - 1600 or 1866 MHz (depending
on the configuration) , synchronous dynamic random-access memory (SDRAM) registered dual inline
memory modules (DIMMs) with error correcting code (ECC).
• The specifications of a DDR3 DIMM are on a label on the DIMM, in the following format.
gggeRxff-PC3-wwwwwm-aa-bb-cc-dd
where:
– ggg is the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)
– eis the number of ranks
1 = single-rank
2 = dual-rank
– x ff is the device organization or bit width (for example, x4, x8, or x16)
4 = x4 organization (4 DQ lines per SDRAM)
8 = x8 organization
16 = x16 organization
– wwwww is the DIMM bandwidth, in MBps
12800 = 12.80 GBps PC3-1600 SDRAMs, 8-byte primary data bus)
14900 = 14.93 GBps PC3-1866 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)
L = Load Reduction DIMM (LR-DIMM)
– aa is the DDR3 SDRAM 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 xxx nRxxx PC3-xxxxx-xx-xx-xx-xx. The numeral in the fourth numerical position indicates whether
the DIMM is single-rank (n=1) or dual-rank (n=2).
• Do not mix registered and unbuffered DIMMs in the server.
• Do not mix load reduced DIMMs with other types of DIMMs in the server.
• DO not mix ECC and non-ECC DIMMs in the server.
• The server supports 1.35-volt (low-voltage) and 1.5-volt DIMMs.
• The server supports a maximum of 16 DIMMs (single-rank and dual-rank) on the base system board.
• The DIMM options that are available for the server are 4 GB, 8 GB, 16 GB, and 32 GB (when available).
• The server supports memory sparing. Memory sparing reserves memory capacity for failover in the event
of a DIMM failure, and the reserved capacity is deducted 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.
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Lenovo System x3650 M4 BDInstallation and Service Guide