Lenovo System x3750 M4, Installation And Service Manual

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where:
– g GB is the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)
– e R is the number of ranks
1R = single-rank
2R = dual-rank
4R = quad-rank
– x f 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
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)
14900 = 14.90 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)
– a is the CAS latency, in clocks at maximum operating frequency
– b is the JEDEC SPD Revision Encoding and Additions level
– c 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 1.35-volt (low-voltage) registered DIMMs and 1.5-volt (standard voltage) registered
DIMMs as follows:
– Supported DIMMs with speeds of 1600 MHz or less support both 1.35 V and 1.5 V operation,
depending on the configuration settings in the Setup utility.
– Supported DIMMs with speeds of 1866 MHz do not support 1.35 V operation. Only 1.5 V operation is
supported.
• Single-device data correction (SDDC) support is available only when 16 GB or 32 GB, x4 DRAM
technology DIMMs are installed in the server.
• The following table provides information about the maximum amount of memory that the server can
support when you fully populate the server and the optional microprocessor and memory expansion
tray by using the supported DIMMs.
Table 5. Maximum supported memory
Number of DIMM connectors Maximum memory
24 DIMMs on system board Up to 768 GB
24 DIMMs on the optional microprocessor and memory
expansion tray Up to 768 GB
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Lenovo System x3750 M4 Installation and Service Guide