PC 100 ram vs. PC 133 ram

Your RAM chip probably is a PC133 chip; PC100 RAM is too slow to be used in your model of Mac, and won't be recognized at all.

(21631)

Hello! The faster 133 chip is backwards compatible and the system uses the slower speed so it should be fine. Tom

Hi

I used a couple of DIMMs in my Quicksilver for a number of years that were PC133 rated, although the Apple System Profiler reported them as being PC100. I never experienced any problems with them and I believe they were used at PC133 speeds.

I've seen a number of explanations for this in the past, including the ASP having a bug, the memory being used at a slower speed and lower latency rather than a faster speed and higher latency, the DIMMS being both PC100 and PC133 compatible and the ASP only reporting the first of these etc.

So long as all the memory is being recognised and you're not experiencing any crashes or freezes, I personally wouldn't worry about it.

If you want to be sure, examine one of the individual chips on the DIMM that's identified as PC-100. If you see -10 or -8 (-08) printed on the chip, then it's a PC-100 DIMM with either 10ns or 8ns chips. If you see -7 (-07) or -7.5, then it's a PC-133 DIMM, which can have either 7ns or 7.5ns chips on it. If it's actually a PC-100 DIMM, then it probably has good quality 8ns chips that can overclock to 7ns or 7.5ns without affecting your G4's performance. The better chip manufacturers (like Micron) will actually test their chips to surpass industry requirements.

Look at this link http://www.pcmech.com/article/sdram-pc100-pc133-and-ddr/

 Cheers, Tom