IBM System x3620 M3 7376 Installation And User Manual page 80

v To confirm that the server supports the DIMM that you are installing, see
v When you install or remove DIMMs, the server configuration information
v The server supports only industry-standard double-data-rate 3 (DDR3), 800,
v The specifications of a DDR3 DIMM are on a label on the DIMM, in the following
v The maximum memory speed is determined by the combination of the
v The following rules apply to DDR3 DIMM speed as it relates to the number of
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System x3620 M3 Type 7376: Installation and User's Guide
http://www.ibm.com/systems/info/x86servers/serverproven/compat/us/.
changes. When you restart the server, the system displays a message that
indicates that the memory configuration has changed.
1066, or 1333 MHz, PC3-10600R-999, synchronous dynamic random-access
memory (SDRAM) registered dual inline memory modules (DIMMs) with error
correcting code (ECC).
format.
ggg eRxff-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
6400 = 6.40 GBps (PC3-800 SDRAMs, 8-byte primary data bus)
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 = 12.80 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
microprocessor, DIMM speed, and the number of DIMMs installed in each
channel.
DIMMs in a channel:
– When you install one DIMM single-rank or dual-rank per channel, the memory
runs at 1333 MHz
– When you install two DIMMs single-rank or dual-rank per channel, the
memory runs at 1066 MHz
– When you install two 1.35 V DIMMs in a channel, the memory runs at 800
MHz. The DIMMs still function at 1.35 V
– When you install quad-rank DIMMs with single-rank or dual-rank DIMMs in the
same channel, the memory runs at 800 MHz
– All channels in a server run at the fastest common frequency