Dell Precision 650 User Manual
Page 61
Back to Contents Page
Memory
Dell Precision™ Workstation 650 and Dell Precision Workstation 450 Service Manual
Memory Installation Guidelines
You can increase your computer memory by installing memory modules on the system board. For information on the type of memory supported by your
computer, see "Specifications" in your User's Guide.
Memory Installation Guidelines
l
Memory module connectors must be upgraded in matched pairs. Memory module connectors 1 and 2 must contain modules of identical size, type, speed,
and number of chips and memory module connectors 3 and 4 must contain modules of identical size, type, speed, and number of chips. To locate the
memory sockets on the system board, see the system board components illustration (for the Dell Precision 450 computer, see "
System Board
Components
" or for the Dell Precision 650 computer, see "
System Board Components
") or the system board label inside your computer.
l
Before you install new memory modules, download the most recent BIOS for your computer from the Dell Support website at support.dell.com.
Memory Module Label
Addressing Memory With 4-GB Configurations
Your computer supports a maximum of 4GB of memory when using four 1-GB DIMMs. Current operating systems, such as Microsoft® Windows® 2000 and
Windows XP, can only utilize a maximum of 4 GB of address space; however, the amount of memory available to the operating system is slightly less than 4
GB. 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 is a list of components that require memory address space:
l
System ROM
l
APIC(s)
l
Integrated PCI devices, such as network connector, SCSI controller, and IEEE 1394 controller
l
PCI and AGP cards
l
The AGP Aperture size specified in system setup
At start-up the BIOS identifies the components that require address space. The BIOS dynamically calculates the amount of reserved address space required. It
then subtracts the reserved address space from 4 GB to determine the amount of usable space.
l
If the total installed computer memory is less than the usable space, all installed computer memory is available for use only by the operating system.
l
If the total installed computer memory is equal to or greater than the usable address space, a small portion of installed memory is available for use by
the operating system.
Removing a Memory Module
1.
Press down and outward on the securing clips.
2.
Grasp the module and pull up.
If the module is difficult to remove, gently ease the module back and forth to remove it from the connector.
CAUTION:
Before you begin any of the procedures in this section, follow the safety instructions in the System Information Guide.