3.2 How to Install a Memory Module
Memory modules for this system are dual inline memory modules (DIMMs). Each
DIMM bank must contain four DIMMs of equal density (for example, four 64-Mbyte
DIMMs) to function properly.Supported DIMM configuration options are 32, 64, and
128 megabytes. See the Sun Enterprise 220R Server Owner’s Guide for more
information about memory.

3.2.1 Configuration Rules

The following memory configuration rules applyto your system:
At least one memory bank (all four bank slots) must be filled for the system to
boot.
DIMMs must be added four at a time within the same bank.
DIMM capacities can differ fromone bank to the next—for example, four
64-Mbyte DIMMs installed inbank 0 and four 128-Mbyte DIMMs installed
in bank 2 is permissible.
Refer to the following diagram for memory locations in your system.
90 Sun Enterprise 220R Server Service Manual ♦January 2000, Revision A