Back to Contents PageMemoryDell Precision™ Workstations 450 and 650 User's GuideMemory Installation GuidelinesRemoving a Memory ModuleAdding a Memory ModuleYou can increase your computer memory by installing memory modules on the system board. For information on the type of memory supported by yourcomputer, see "Specifications."1. Shut down the computer through the Start menu.2. Ensure that your computer and attached devices are turned off. If your computer and attached devices did not automatically turn off when you shutdown your computer, turn them off now.3. Disconnect any telephone or telecommunication lines from the computer.4. Disconnect your computer and all attached devices from electrical outlets, and then press the power button to ground the system board.5. If you have installed a padlock through the padlock ring on the back panel, remove the padlock.6. Open the computer cover.Memory Installation Guidelinesl 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 locatethe memory sockets on the system board, see the system board components illustration (for the Dell Precision 450 computer, see "System BoardComponents" 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 LabelAddressing Memory With 4-GB ConfigurationsYour computer supports a maximum of 4GB of memory when using four 1-GB DIMMs. Current operating systems, such as Microsoft® Windows® 2000 andWindows 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 4GB. Certain components within the computer require address space in the 4-GB range. Any address space reserved for these components cannot be used bycomputer memory. The following is a list of components that require memory address space:l System ROMl APIC(s)l Integrated PCI devices, such as network connector, SCSI controller, and IEEE 1394 controllerl PCI and AGP cardsl The AGP Aperture size specified in system setupCAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the System Information Guide.NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug it from the network wall jack.CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover.NOTICE: Before touching anything inside your computer, ground yourself by touching an unpainted metal surface, such as the metal at the back of thecomputer. While you work, periodically touch an unpainted metal surface to dissipate any static electricity that could harm internal components.