"'PC-100' is an Intel-driven standard for DIMMs compatible with Intel 100 MHz systems. Intel requires prominent marking of the DIMM as PC-100, and requires the speed code to be listed as well. Power Macintosh G3 is compatible with 3-2-3 (slowest), 3-2-2, and 2-2-2 (fastest) speed codes. Power Macintosh G3 will read the presence detect ROM for information about all the DIMMs installed in the machine, and set memory timing equal to the slowest DIMM. Therefore, for maximum performance use only 2-2-2 speed codes. However, the difference in application performance between the speed codes is small. Power Macintosh G3 typically ships with a single 3-2-2 DIMM. This may change over time.
PowerMacintosh G3 (Blue and White) Developer Notes
The DIMM modules used in any previous Power Macintosh or Power Macintosh G3 computer model are not compatible with the Power Macintosh G3 described in this note. The SDRAM DIMM modules must be PC-100 compliant, 168-pin, 3.3-volt, unbuffered, and rated at 125 MHz (8 ns) or faster."