Sun Microsystems 220R manual About Memory, Configuration Rules

About Memory

The system’s main logic board provides 16 slots for high-capacity dual inline memory modules (DIMMs). The system supports Sun standard 200-pin, 5-volt,

60-nanosecond memory modules. Modules of 32-, 64-, or 128-Mbyte capacities can be installed in the system. Total main memory is expandable up to 2 Gbytes.

Memory slots are organized into four banks (banks 0 through 3), with each bank comprising four slots.

The system reads from, or writes to, all four DIMMs in a bank at the same time. DIMMs, therefore, must be added four at a time in the same bank. For the DIMM bank organization and numbering scheme see “DIMM Failure” on page 152.

Memory modules are delicate. Ensure that you take appropriate precautions to avoid damaging them through electrostatic discharge. The memory modules must be replaced or installed by a qualified service provider; for information about removing and installing DIMMs, see the Sun Enterprise 220R Server Service Manual.

Configuration Rules

The following memory configuration rules apply to your system:

■At least one memory bank (all four bank slots) must be filled for the system to boot

■Each bank used must have four identical capacity DIMMs installed (for example, four 64-Mbyte DIMMs or four 128-Mbyte DIMMs)

■DIMMs must be added four at a time within the same bank

DIMM capacities can differ from one bank to the next—for example, four 64-Mbyte DIMMs installed in bank 0 and four 128-Mbyte DIMMs installed in bank 2 is permissible

Caution –DIMMs are made of electronic components that are extremely sensitive to static electricity. Static from your clothes or work environment can destroy the modules. Do not remove any DIMM from its antistatic packaging until you are ready to install it on the system board. Handle the modules only by their edges. Do not touch the components or any metal parts. Always wear a grounding strap when you handle the modules.

66 Sun Enterprise 220R Server Owner’s Guide • October 1999