User manual DELL PRECISION 620 Supplementary Guide

[. . . ] Dell Precision 620 systems support dual, direct, Rambus dynamic random-access memory (RDRAM) modules. NOTES: Dell recommends that only a technically knowledgeable person perform this procedure. You must also be familiar with removing the system cover and locating the RIMMs. [. . . ] In addition, take note of these safety guidelines when appropriate: · When you disconnect a cable, pull on its connector or on its strain-relief loop, not on the cable itself. Some cables have a connector with locking tabs; if you are disconnecting this type of cable, press in on the locking tabs before disconnecting the cable. As you pull connectors apart, keep them evenly aligned to avoid bending any connector pins. Also, before you connect a cable, make sure both connectors are correctly oriented and aligned. Hold a component such as a RIMM by its edges, not by its pins. · Upgrading System Memory NOTICE: Before you upgrade the RIMMs, you must upgrade the BIOS. This computer has two memory expansion cards (MECs), both consisting of four sockets: RIMM1_A, RIMM2_A, RIMM3_B, and RIMM4_B. On each MEC, sockets RIMM1_A and RIMM2_A comprise channel A, and sockets RIMM3_B and RIMM4_B comprise channel B. Dell Precision 620 systems support a maximum of eight RIMMs (four RIMMs per MEC) for up to 3 gigabytes (GB) of total memory. NOTE: Although you can insert 512-megabyte (MB) RIMMs in each socket, the BIOS revision only supports a maximum of 3 GB. Figure 1 shows the RIMMs and RIMM sockets. support. dell. com System Memory Upgrade 3 MEC cover RIMM1_A RIMM2_A channel A riser board RIMM3_B RIMM4_B channel B Figure 1. RIMM Socket Designations 4 System Memory Upgrade RIMM Installation Guidelines You must install RIMMs in pairs. This means that the RIMM in each socket on one MEC must be the same memory capacity, density, and speed as the corresponding RIMM in the same socket on the other MEC. Also, for either channel A or B of each MEC, if one socket contains a RIMM, then the other socket must contain either another RIMM or a continuity RIMM (CRIMM). As an example, if you install only one pair of RIMMs in the RIMM1_A socket of each MEC, then you must install a CRIMM in socket RIMM2_A of each MEC. Channel B (sockets RIMM3_B and RIMM4_B) may remain empty, or it may contain one or two CRIMMs per MEC (see Figure 1). However, if channel A contains two RIMMs and you want to install additional RIMMs, the preceding rules also apply for channel B. [. . . ] If you wait too long and the operating system begins to load into memory, allow the system to complete the load operation; shut down the system and try again. NOTE: For instructions on using system setup, see the User's Guide. Press <Enter> to access the System Security option's pop-up menu. [. . . ]