Lenovo 5457 Installation And Service Manual page 277

Attention: Static electricity that is released to internal server components when the server is powered-on
might cause the server to stop, which could result in the loss of data. To avoid this potential problem,
always use an electrostatic-discharge wrist strap or other grounding system when working inside the
server with the power on.
• The specifications of a DDR3 DIMM are on a label on the DIMM, in the following format.gggeRxff-PC3-
wwwwwm-aa-bb-cc
where:
– ggg is the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)
– e is the number of ranks
– 1 = single-rank
– 2 = dual-rank
– 4 = quad-rank
– ff is the device organization (bit width)
– 4 = x4 organization (4 DQ lines per SDRAM)
– 8 = x8 organization
– 16 = x16 organization
– wwwww is the DIMM bandwidth, in MBps
– 8500 = 8.53 GBps (PC3-1066 SDRAMs, 8-byte primary data bus)
– 10600 = 10.66 GBps (PC3-1333 SDRAMs, 8-byte primary data bus)
– 12800 = 12.8 GBps (PC3-1600 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)
– 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
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).
Unbuffered DIMMs (UDIMMs)
The following notes provide information that you must consider when you install UDIMMs:
• The memory channels run at the lowest common frequency of the DIMMs installed.
• The UDIMM options that are available for the server are 1 GB, 2 GB, 4 GB, and 8 GB (when available)
DIMMs.
• The server supports up to two single-rank or dual-rank UDIMMs per channel.
The following table lists the supported UDIMM population.
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Chapter 6 Removing and replacing components
265