Memory Installation (Without Memory Riser Cards)Fully buffered DDR2 memory modules can also be installed in pairs of two; in this case, the computer will continue to operate, but with a slight reduction inperformance. The pairs must be matched in size, rank, and organization.Install memory modules in order of their labels on the system board; matched sets of four should be installed first into DIMM slots 1-4 and then into DIMM slots5-8 on the system board. Pairs of memory should be first installed into slots DIMM_1, and DIMM_2, then DIMM_3 and DIMM_4, and so on.Installing Memory Without Memory Riser Cards1. Follow the procedures in Before You Begin.2. Remove the computer cover (see Removing the Computer Cover).1 fully buffered DIMM2 fully buffered DIMM with full-length heat spreaders3 information labelNOTICE: Do not install non-ECC, unbuffered, or non-fully-buffered memory modules. Doing so may cause the system not to boot.CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover.NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of yourcomputer's electronic components. You can do so by touching an unpainted metal surface on the computer.CAUTION: Your computer is heavy (it has an approximate minimum weight of 55 lbs) and can be difficult to maneuver. Seek assistance beforeattempting to lift, move, or tilt it; this computer requires a two-man lift. Always lift correctly to avoid injury; avoid bending over while lifting. Seeyour Product Information Guide for other important safety information.CAUTION: The computer stand should be installed at all times to ensure maximum system stability. Failure to install the stand could result in thecomputer tipping over, potentially resulting in bodily injury or damage to the computer.