Hardware Reference Guide
should be populated with the other two 1 GB DIMMs. With this conguration, 4 GB runs as dual-channel
and 1 GB runs as single-channel.
● In any mode, the maximum operational speed is determined by the slowest DIMM in the system.
IMPORTANT: You must disconnect the power cord and wait approximately 30 seconds for the power to drain
before adding or removing memory modules. Regardless of the power state, voltage is always supplied to the
memory modules as long as the computer is plugged into an active AC outlet. Adding or removing memory
modules while voltage is present can cause irreparable damage to the memory modules or system board.
The memory module sockets have gold-plated metal contacts. When upgrading the memory, it is important
to use memory modules with gold-plated metal contacts to prevent corrosion, oxidation, or both resulting
from having incompatible metals in contact with each other.
Static electricity can damage the electronic components of the computer or optional cards. Before beginning
these procedures, make sure that you are discharged of static electricity by briey touching a grounded metal
object. For more information, see
Electrostatic discharge on page 44.
When handling a memory module, be careful not to touch any of the contacts. Doing so may damage the
module.
1. Remove or disengage any security devices that prohibit opening the computer.
2. Remove all removable media, such as compact discs or USB ash drives, from the computer.
3. Turn o the computer properly through the operating system, and turn o any external devices.
4. Disconnect the power cord from the AC outlet and disconnect any external devices.
IMPORTANT: You must disconnect the power cord and wait approximately 30 seconds for the power to
drain before adding or removing memory modules. Regardless of the power state, voltage is always
supplied to the memory modules as long as the computer is plugged into an active AC outlet. Adding or
removing memory modules while voltage is present may cause irreparable damage to the memory
modules or system board.
5. If the computer is on a stand, remove the computer from the stand.
6. Remove the computer access panel.
WARNING! To reduce risk of personal injury from hot surfaces, allow the internal system components
to cool before you touch them.
7. Disconnect the power and data cables from the rear of the drives in the drive cage.
14 Chapter 2 Hardware upgrades