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Memory

Dell™ OptiPlex™ 745 User's Guide

  DDR2 Memory Overview

  Addressing Memory With 4-GB or Greater Configurations (32-bit Operating Systems Only)

  Removing Memory

  Installing Memory


Your computer supports non-ECC DDR2 memory only. For more information on the type of memory supported by your computer, see the "Memory" section of the specifications for your computer:

NOTICE: Before you install new memory modules, download the most recent BIOS for your computer from the Dell Support website at support.dell.com.
NOTE: Memory purchased from Dell is covered under your computer warranty.

DDR2 Memory Overview

Dual-channel DDR2 memory modules should be installed in pairs of matched memory size. If the DDR2 memory modules are not installed with the same amount of memory in each channel, the computer will continue to operate, but with a slight reduction in performance. See the label in the upper-right corner of the module to determine the module's capacity.

NOTICE: Do not install ECC memory modules. Doing so may cause the system not to boot or otherwise impact performance.
NOTE: Always install DDR2 memory modules in the order indicated on the system board.

The recommended memory configurations are:

or

or

Be sure to install a single memory module in DIMM1, the connector closest to the processor, before you install modules in the other connectors.

NOTE: The ultra small form factor computer has only two slots which are considered an interleaved pair. The mini tower, desktop, and small form factor computers have four slots.

Mini Tower, Desktop, and Small Form Factor Matched Pairs

A

matched pair of memory modules in connectors DIMM1 and DIMM2 (white securing clips)

B

matched pair of memory modules in connectors DIMM3 and DIMM4 (black securing clips).


Addressing Memory With 4-GB or Greater Configurations (32-bit Operating Systems Only)

This computer supports a maximum of 8 GB of memory. Current 32-bit operating systems, such as Microsoft® Windows® XP, can use a maximum of 4 GB of address space; however, the amount of memory available to the operating system is less than that installed. Certain components within the computer require address space in the 4-GB range. Any address space reserved for these components cannot be used by computer memory.

The following components require memory address space:

At start-up, the BIOS identifies the components that require address space. The BIOS dynamically calculates the amount of reserved address space required. The BIOS then subtracts the reserved address space from 4 GB to determine the amount of usable space.


Removing Memory

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
NOTICE: If you remove your original memory modules from the computer during a memory upgrade, keep them separate from any new modules that you may have, even if you purchased the new modules from Dell. If possible, do not pair an original memory module with a new memory module. Otherwise, your computer may not start properly.
You should install your original memory modules in pairs either in connectors DIMM1 and DIMM2 or connectors DIMM3 and DIMM4.
NOTICE: Removing memory modules from DIMM2 and DIMM4 on the desktop computer requires you to remove the optical drive (see Drives). Failure to do so may cause damage to the memory module and the DIMM socket.
  1. Follow the procedures in Before You Begin.

  2. If you are using a desktop computer, remove the optical drive (see Optical Drive).

  3. Carefully press out the securing clip at each end of the memory module connector.

1

memory module

2

securing clip (2)

  1. Remove the memory module. If you are replacing a memory module, see Installing Memory.

  2. If you are using a desktop computer, replace the optical drive (see Optical Drive).

  3. Replace the computer cover (see Replacing the Computer Cover).


Installing Memory

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your computer's electronic components. You can do so by touching an unpainted metal surface on the computer chassis.
NOTE: Memory purchased from Dell is covered under your computer warranty.
  1. Follow the procedures in Before You Begin.

  2. If you are using a desktop computer, remove the optical drive (see Optical Drive).

  3. Press out the securing clip at each end of the memory module connector.

1

memory connector closest to processor

2

securing clips (2)

3

connector

  1. Align the notch on the bottom of the module with the crossbar in the connector.

1

cutouts (2)

2

memory module

3

notch

4

crossbar

NOTICE: To avoid damage to the memory module, press the module straight down into the connector while you apply equal force to each end of the module.
  1. Insert the module into the connector until the module snaps into position.

If you insert the module correctly, the securing clips snap into the cutouts at each end of the module.

  1. If you are using a desktop computer, replace the optical drive (see Optical Drive).

  2. Replace the computer cover (see Replacing the Computer Cover).

  3. The computer detects that the new memory does not match the existing configuration information and generates the following message:

The amount of system memory has changed.
Strike the F1 key to continue, F2 to run the setup utility

  1. Press <F2> to enter system setup and check the value for System Memory.

The computer should have changed the value of System Memory to reflect the newly installed memory. Verify the new total. If it is correct, skip to step 11.

  1. If the memory total is incorrect, turn off and disconnect your computer and devices from their electrical outlets. Open the computer cover and check the installed memory modules to ensure that they are seated properly in their sockets. Then repeat steps 7, 8, and 9.

  2. When the System Memory total is correct, press <Esc> to exit system setup.

  3. Run the Dell Diagnostics (see Dell Diagnostics) to verify that the memory modules are operating properly.


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