Lenovo 3633 Installation And Service Manual page 115

gggGBpheRxff PC4-wwwwaa-mccd-bb
where:
– gggGB is the total capacity of the DIMM (for example, 1 GB, 2 GB, or 4 GB)
– pheR is the number of package ranks and number of logical ranks per package rank
p has the following variables:
– 1 = 1 package rank of SDRAMs installed
– 2 = 2 package ranks of SDRAMs installed
– 3 = 3 package ranks of SDRAMs installed
– 4 = 4 package ranks of SDRAMs installed
– he: blank for monolithic DRAMs and others for modules using stacked DRAM.
h is the DRAM package type. It has the following variables:
– D = multi-load DRAM stacking (DDP)
– Q = multi-load DRAM stacking (QDP)
– D = single load DRAM stacking (3DS)
e: blank for SDP, DDP and QDP and others for modules using 3DS stacks, logical ranks per package
rank
It has the following variables:
– 2 = 2 logical ranks in each package rank
– 4 = 4 logical ranks in each package rank
– 8 = 8 logical ranks in each package rank
– xff is the device organization or bit width of SDRAMs (for example, x4, x8, or x16)
– x4 = x4 organization (four DQ lines per SDRAM)
– x8 = x8 organization
– x16 = x16 organization
– wwww is the DIMM speed, in MBps (for example, 2133, 2400, 2666, 2933, or 3200)
aa is the SDRAM speed grade
– m is the DIMM type
– E = Unbuffered DIMM (UDIMM) (x64-bit primary data bus) with ECC (x8-bit module data bus)
– L = Load Reduced DIMM (LRDIMM) (x64-bit primary data bus) with ECC (x8-bit module data bus)
– R = Registered DIMM (RDIMM) (x64-bit primary data bus) with ECC (x8-bit module data bus)
– U = Unbuffered DIMM with no ECC (x64-bit primary data bus)
cc is the reference design file for the design of the DIMM
d is the revision number of the used reference design
– bb is the JEDEC SPD Revision Encoding and Additions level
To locate the DIMM slots on the system board, see
The following sections provide additional information specific to unbuffered DIMMs that you must consider.
Unbuffered DIMMs (UDIMMs)
The following tips provide information that you must consider when you install UDIMMs.
"System-board connectors" on page
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Chapter 7 Removing and installing server components
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