PC100 SDRAM vs PC133 SDRAM for G4 AGP Mac

Most PC133 memory will work in machines designed for PC100. if they say it will work in your Mac, they will replace if it doesn't. It won't run any faster than PC100, but is sometimes cheaper than PC100 because it is made in larger quantities. I have used PC133 RAM in a PC100 rated G3 iMac.

Hi-

Either one, (as long as Mac compatible) will work fine. The base spec is PC100, but PC133 is backward compatible, and will cause no harm. It won't work any faster than the equivalent PC100, nor any slower. Mixing the two is also not a problem.
I have 1 PC100 512mb module, and 3 PC133 512mb modules in my AGP G4. No problems.
Same in a G4 Gigabit Ethernet- mixed PC100/133 and no troubles.

PC100 is sometimes hard to find, and, as Malcolm suggests, there are more of the PC133 chips available, resulting in many vendors carrying only the PC133 for older G4's.

Its based on bus speed...it's a 100 mhz bus architecture so the RAM speed should be 100 mhz. Some 133 Mhz modules are still compatible, but because of powermac's 100 mhz bus, they still only run @ 100 mhz. Thus, for any computer, RAM speed should match system bus speed.