Adding and Replacing Parts 179Memory Installation (With Optional Memory Riser Cards)NOTICE: The memory shroud holds the (optional) memory risers in place; itsthumbscrews must be sufficiently tight in order to secure the riser cards and toavoid damage.The four memory riser cards that you received with your computer areconnected together in sets of two. Do not attempt to disconnect the memoryriser cards from each other. Each memory riser card is numbered in the upperleft hand corner. These numbers indicate which DIMM slot on the systemboard each riser card must be inserted into. Only the DIMM_1-4 slots (theslots with the white securing clips) on the system board can be used with theriser cards. The other slots (DIMM_5-8) must be left vacant.You must remove the memory riser cards from the computer in order toinstall memory on them. The memory slots on each riser card are numberedDIMM_1-DIMM_4. Memory must be installed on these cards in the orderthat they are numbered; that is, DIMM_1 on riser card 1 must be populatedbefore DIMM_1 is populated on any other card. DIMM_1 must be populatedon each card before DIMM_2 can be populated on riser card 1, and so on.Memory must be installed in sets of four with one of the four on each risercard.
