Memory Module Installation - Lenovo ThinkServer sd350 Installation And Service Manual

If you are instructed to return the server component or optional device, follow all packaging instructions,
and use any packaging materials for shipping that are supplied to you.

Memory module installation

The following notes describe the types of DIMMs that the server supports and other information that you
must consider when you install DIMMs.
• Confirm that the server supports the DIMM that you are installing (see http://www.lenovo.com/us/en/
serverproven/).
• When you install or remove DIMMs, the server configuration information changes. When you restart the
server, the system displays a message that indicates that the memory configuration has changed. You
can use the Setup utility to view the server configuration information, see "Using the Setup utility" on
page 34 for more information.
• The server supports only industry-standard double-data-rate 4 (DDR4), 2400 MHz, PC4-19200
(single-rank or dual-rank), unbuffered or synchronous dynamic random-access memory (SDRAM) dual
inline memory modules (DIMMs) with error correcting code (ECC).
• The maximum operating speed of the server is determined by the slowest DIMM in the server.
• If you install a pair of DIMMs in DIMM connectors 1 and 3, the size and speed of the DIMMs that you
install in DIMM connectors 1 and 3 must match each other. However, they do not have to be the same
size and speed as the DIMMs that are installed in DIMM connectors 2 and 4.
• You can use compatible DIMMs from various manufacturers in the same pair.
• The specifications of a DDR4 DIMM are on a label on the DIMM, in the following format.
• gggGBpheRxff PC4-wwwwaa-mccd-bb
where:
– gggGB is the total capacity, in gigabytes, for primary bus (ECC not counted) 4GB, 8GB, 16GB, etc.
(no space between digits and units)
– pheR is the number of package ranks of memory installed and number of logical ranks per package rank
– p =
• 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, else for modules using stacked DRAM:
• h = DRAM package type
– D = multi-load DRAM stacking (DDP)
– Q = multi-load DRAM stacking (QDP)
– S = single load DRAM stacking (3DS)
• e = blank for SDP, DDP and QDP, else modules using 3DS stacks, logical ranks per package rank
– 2 = 2 logical ranks in each package rank
– 4 = 4 logical ranks in each package rank
– 8 = 8 logical ranks in each package rank
– R = rank(s)
– xff = Device organization (data bit width) of SDRAMs used on this assembly
• x4 = x4 organization (4 DQ lines per SDRAM)
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Lenovo ThinkServer sd350 Server Type 5493, Lenovo ThinkServer n400 Enclosure Type 5495Installation and Service Guide