access memory (SDRAM) dual inline memory modules (DIMMs) with error correcting code (ECC). See
http://www.lenovo.com/ serverproven/ for a list of supported memory modules for the server.
– The specifications of a DDR4 DIMM are on a label on the DIMM, in the following format.
gggggeRxff
PC4
v
-
wwwwwm
-
aa
-
bb
-
ccd
where:
–
ggggg
is the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)
–
eR
is the number of ranks
1R = single-rank
2R = dual-rank
4R = quad-rank
–
xff
is the device organization (bit width)
x4 = x4 organization (4 DQ lines per SDRAM)
x8 = x8 organization
x16 = x16 organization
–
v
is the SDRAM and support component supply voltage (VDD)
• Blank = 1.2 V specified
–
wwwww
is the DIMM bandwidth, in MBps
12800 = 12.80 GBps (DDR4-1600 SDRAMs, 8-byte primary data bus)
14900 = 14.93 GBps (DDR4-1866 SDRAMs, 8-byte primary data bus)
17000 = 17.00 GBps (DDR4-2133 SDRAMs, 8-byte primary data bus)
–
m
is the DIMM type
L = Load Reduction DIMM (LRDIMM)
R = Registered DIMM (RDIMM)
–
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 PC4v-xxxxxx-xx-xx-xxx. The numeral in the sixth numerical position indicates
whether the DIMM is single-rank (n=1), dual-rank (n=2), or quad-rank (n=4).
• The following rules apply to DDR4 RDIMM speed as it relates to the number of RDIMMs in a channel:
– When you install 1 RDIMM per channel, the memory runs at 2133 MHz
– When you install 2 RDIMMs per channel, the memory runs at 1866 MHz
– When you install 3 RDIMMs per channel, the memory runs at 1600 MHz
– All channels in a server run at the fastest common frequency
– Do not install registered and load reduction DIMMs in the same server
• The maximum memory speed is determined by the combination of the microprocessor, DIMM speed,
DIMM type, Operating Modes in UEFI settings, and the number of DIMMs installed in each channel.
• In two-DIMM-per-channel configuration, the compute node automatically operates with a maximum
memory speed of up to 1600 MHz when the following condition is met:
Removing and replacing server components
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Summary of Contents for NeXtScale n1200
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Page 869: ...Taiwan Class A compliance statement Appendix E Notices 855 ...
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Page 878: ...Part Number SP47A31725 Printed in China 1P P N SP47A31725 1PSP47A31725 ...
