This article describes a situation where Apple System Profiler reports slow memory in computers with multiple PC-100 RAM modules.

Symptom

When two SO-DIMM modules with different CAS Latency values are installed, Apple System Profiler reports that one of the SO-DIMMs installed is slow.

Affected Products

• All Apple products with PC-100 or PC-133 RAM (PowerBook G3 (FireWire), Power Mac G4)

Solution :

Apple System Profiler identifies the RAM as either PC-100-222S, or PC-100-322S. These memory modules meet Apple's memory specification for PC-100 memory. The PC-100-322S has a CAS latency rating of 3 rather than 2. This will not impact the performance of the computer.

If Apple System Profile identifies the RAM as PC-100-333S, it is actually PC-66 memory or an earlier form of PC-100 memory that is not qualified for use in the PowerBook (Firewire).

Note : If both memory modules are the same speed, it is only reported once.

Future revisions of Apple System Profiler will not report slow memory if both memory modules meet the memory specification for Apple computers.