IBM IntelliStation M Pro, Installation Manual

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4. The amount of usable memory will be reduced depending on the system
configuration. A certain amount of memory must be reserved for system
resources. The BIOS will display the total amount of installed memory and the
amount of configured memory.
5. Your computer comes with either one or two 256 MB, 512 MB, or 1 GB memory
DIMM installed. If your system has one DIMM installed, when you install an
additional DIMM, it must be installed in DIMM 3 memory connector, and must
be the same size, speed, type, and technology as the DIMM installed in DIMM 1
memory connector. You can mix compatible DIMMs from various manufacturers.
When one DIMM is installed in the system, the system runs as a single-channel
machine. When you add a DIMM in DIMM 3 memory connector, your system
defaults to a dual-channel machine.
6. DIMMs must be installed in matched pairs. The first pair of DIMMs you install in
DIMM 1 and DIMM 3 memory connectors must be the same size, speed, type,
and technology. You can mix compatible DIMMs from various manufactures. If
you install a second pair of DIMMs in DIMM 2 and DIMM 4 memory connectors,
they do not have to be the same size, speed, type, and technology as the
DIMMs installed in DIMM 1 and DIMM 3 memory connectors. However, the size,
speed, type, and technology of the DIMMs you install in DIMM 2 and DIMM 4
memory connectors must match each other.
7. Install only 2.5 V, 184-pin, double-data-rate (DDR) 266, PC2700 or PC3200,
unbuffered synchronous dynamic random-access memory (SDRAM) with error
correcting code (ECC) DIMMs. These DIMMs must be compatible with the latest
PC2700 or PC3200 SDRAM unbuffered DIMM specification. For a list of
supported options for your computer, go to http://www.ibm.com/pc/; then, select
your country and navigate to the list of options for your computer.
Complete the following steps to install a DIMM:
1. Read the safety information beginning on page v, and “Handling
static-sensitive devices” on page 11.
2. Turn off the computer and all attached devices (see “Turning off the computer”
on page 43); then, disconnect all power cords and external cables.
3. Remove the side cover (see “Removing the side cover” on page 26).
4. Remove the support bracket (see “Removing and installing the support
bracket” on page 27).
5. You might find it easier to install memory modules if you rotate the drive cage
out of the computer. Grasp the drive cage and rotate it until it locks into place.
6. Locate the DIMM connectors on the system board. Determine the connectors
into which you will install the DIMMs. Remember, DIMM 1 and DIMM 3 must
be paired together (and must be the first pair installed) and DIMM 2 and DIMM
4 must be paired together. The following illustration shows the DIMM
installation sequence.
Memory installation sequence
DIMMs Slots
1 DIMM 1
2 DIMMs 1, 3
4 DIMMs 1, 2, 3, 4
7. Open the retaining clips and, if necessary, remove any existing DIMM.
Chapter 2. Installing the hardware
37