Installing A Memory Module - IBM x3550 M4 Type 7914 Installation And Service Manual

Installing a memory module

The following notes describe the types of DIMMs that the server supports and
other information that you must consider when you install DIMMs.
v 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.
v The server supports only industry-standard double-data-rate 3 (DDR3), 1066,
1333, 1600, or 1866 MHz, PC3-8500, PC3-10600, PC3-12800, or PC3-14900
registered or unbuffered, synchronous dynamic random-access memory
(SDRAM) dual inline memory modules (DIMMs) with error correcting code
(ECC). See http://www.ibm.com/systems/info/x86servers/serverproven/
compat/us/ for a list of supported memory modules for the server.
– The specifications of a DDR3 DIMM are on a label on the DIMM, in the
following format.
ggggg eRxff PC3v-wwwwwm-aa-bb-ccd
where:
- ggggg is the total capacity of the DIMM (for example, 1 GB, 2 GB, or 4 GB)
- 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)
v Blank = 1.5 V specified
v L = 1.35 V specified, 1.5 V operable
Note: Values for these voltages are "specified" which means the device
characteristics such as timing are supported at this voltage. Values are
"operable" which means that the devices can be operated safely at this
voltage. However, device characteristics such as timing may not be
guaranteed. All devices must be "tolerant" of the highest DDR3 nominal
voltage of 1.5 V, meaning that they may not operate at 1.5 V but may be
powered at that voltage without damage to the devices.
- wwwww is the DIMM bandwidth, in MBps
6400 = 6.40 GBps (DDR3-800 SDRAMs, 8-byte primary data bus)
8500 = 8.53 GBps (DDR3-1066 SDRAMs, 8-byte primary data bus)
10600 = 10.66 GBps (DDR3-1333 SDRAMs, 8-byte primary data bus)
12800 = 12.80 GBps (DDR3-1600 SDRAMs, 8-byte primary data bus)
14900 = 14.93 GBps (DDR3-1866 SDRAMs, 8-byte primary data bus)
- m is the DIMM type
E = Unbuffered DIMM (UDIMM) with ECC (x72-bit module data bus)
L = Load Reduction DIMM (LRDIMM)
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
Chapter 6. Removing and replacing components
237