Back to Contents PageRemoving and Installing PartsDell™ Dimension™ XPS Service ManualMemoryYou can increase your computer memory by installing memory modules on the system board. For information on the type of memory supported by yourcomputer, see "Memory."DDR Memory OverviewDDR memory modules should be installed in pairs of matched memory size. This means that if you purchased your computer with 256 MB of memory installedand you want to add another 256 MB of memory, you must install it in the appropriate connector. If the DDR memory modules are not installed in matchedpairs, the computer will continue to operate, but with a slight reduction in performance.The recommended memory configurations are:l A pair of matched memory modules installed in connectors DIMM1 and DIMM2orl A pair of matched memory modules installed in connectors DIMM1 and DIMM2 and another matched pair installed in connectors DIMM3 and DIMM4Additional memory recommendations include:l Do not install ECC memory modules.l Be sure to install a single memory module in DIMM 1 or the connector closest to the processor before you install modules in the other connectors.Memory Installation GuidelinesMemory PCI CardsAGP Cards DrivesProcessor Airflow Shroud ProcessorSystem Board Power SupplyFront Panel Drive DoorBatteryNOTE: DDR 333 memory operates at 320-MHz when used with an 800-MHz front-side bus processor.NOTE: Always install DDR memory modules in the order indicated on the system board.