IBM 6868 User Guide - Page 84

Accessing the system board To access the system board, it helps to place the computer on its side on a table. You might need to remove some parts that impede your access to components on the system board. When disconnecting cables, it is important to note where they attach, so you can correctly reattach them later. For information on removing the computer cover, see "Disconnecting cables and removing the cover" on page 64. Installing memory You can add memory to the IntelliStation M Pro to increase system performance using Rambus inline memory modules (RIMMs). There are four connectors (RIMM 1, RIMM 2, RIMM 3, and RIMM 4) for installing Rambus memory. The maximum amount of system memory the IntelliStation M Pro supports is 2 GB. The IBM-installed RIMMs that come with your computer are Rambus dynamic random access memory (RDRAM) modules. They are either non-error checking and correction (non-ECC) modules or error checking and correction (ECC) modules. When installing or replacing RIMMs, take the following information into consideration: Rambus memory is divided up into two channels (channels A and B). RIMM connectors 1 and 2 are on channel A and RIMM connectors 3 and 4 are on channel B. Each channel must contain the same amount of memory. Each RIMM connector supports a maximum of 512 MB of memory. Install only ECC RIMMs to enable ECC. If you use ECC and non-ECC memory together, all memory will function as non-ECC. RIMM connectors do not support dual inline memory modules (DIMMs). Any connector that does not have a memory RIMM installed must have a continuity RIMM (C-RIMM) installed. A C-RIMM is used to continue the connection for a RIMM connector that does not have memory installed in it. Use PC600 (300 MHz) or PC800 (400 MHz) RIMMs. Both can be used in the same computer but when there is a mix, all memory will run at the rate of the slowest RIMM. 70 IntelliStation User Guide