IBM System x3550 M3 Type 4254 Problem Determination And Service Guide

Note: If you install two supported DDR3-1333 DIMMs in each channel on server
models with an Intel Xeon X5570 microprocessor, you must use the ASU tool to
set the server to operate at 1333 MHz in two-DIMM-per-channel (2DPC)
configuration (see “Activating 1333 MHz operation in two-DIMM-per-channel
configuration” on page 272 for more information).
v The server supports a maximum of 18 single-rank or dual-rank RDIMMs. The
server supports up to 12 single-rank or dual-rank UDIMMs or quad-rank
RDIMMs.
Note: To determine the type of a DIMM, see the label on the DIMM. The
information on the label is in the format xxxxx nRxxx PC3-xxxxx-xx-xx-xxx. The
numeral in the sixth numerical position indicates whether the DIMM is single-rank
(n=1), dual-rank (n=2), or quad-rank (n=4).
v The server supports three single-rank or dual-rank DIMMs per channel. The
server supports a maximum of two quad-rank RDIMMs per channel. The
following table shows an example of the maximum amount of memory that you
can install using ranked DIMMs:
Table 13. Maximum memory installation using ranked DIMMs
Number of DIMMs DIMM type DIMM size Total memory
12 Single-rank UDIMMs 2 GB 24 GB
12 Dual-rank UDIMMs 4 GB 48 GB
18 Single-rank RDIMMs 2 GB 36 GB
18 Dual-rank RDIMMs 2 GB 36 GB
18 Dual-rank RDIMMs 4 GB 72 GB
18 Dual-rank RDIMMs 8 GB 144 GB
12 Quad-rank RDIMMs 16 GB 192 GB
v The RDIMM options that are available for the server are 2 GB, 4 GB, 8 GB, and
16 GB. The server supports a minimum of 2 GB and a maximum of 192 GB of
system memory using RDIMMs.
For 32-bit operating systems only: Some memory is reserved for various
system resources and is unavailable to the operating system. The amount of
memory that is reserved for system resources depends on the operating system,
the configuration of the server, and the configured PCI devices.
v The UDIMM options that are available for the server are 2 GB and 4 GB. The
server supports a minimum of 2 GB and a maximum of 48 GB of system memory
using UDIMMs.
Note: The amount of usable memory is reduced depending on the system
configuration. A certain amount of memory must be reserved for system
resources. To view the total amount of installed memory and the amount of
configured memory, run the Setup utility. For additional information, see
“Configuring the server” on page 255.
v A minimum of one DIMM must be installed for each microprocessor. For
example, you must install a minimum of two DIMMs if the server has two
microprocessors installed. However, to improve system performance, install a
minimum of three DIMMs for each microprocessor.
v DIMMs in the same channel must be the same size, speed, type, and technology
to ensure that the server will operate correctly.
v When you install one quad-rank RDIMM in a channel, install it in the DIMM
connector furthest away from the microprocessor.
196 IBM System x3550 M3 Types 4254 and 7944: Problem Determination and Service Guide

IBM System x3550 M3 Type 4254 Specifications

General

Brand	IBM
Model	System x3550 M3 Type 4254
Category	Server
Language	English