SDRAM for Notebooks

There are some 66MHz motherboard/PC133 RAM combinations that won't work. PC133 ram was popular because it was supposed to also work with motherboards with 66 & 100 MHz FSB's, but I've seen times when it didn't. One other possibility is that even if it works, it may run a bit slower than if you bought the 66MHz RAM.

But I'd just buy the PC133 SDRAM and see what happens.

PC133 SDRAM should work fine. The PC rating is the the max speed it is guarenteed to work at. A PC133 stick of RAM on a motherboard running at PC66 will operate at PC66. It will not run any slower.

Does PC133 RAM use a 3x multiplier? Maybe I'm getting confused. But I think with some odd old motherboards you might get speeds of only near 45 MHz from your PC133 RAM. I've never been into overclocking RAM though, & I may be getting this all wrong.

However, I have seen 66MHz motherboards that didn't run PC133 RAM. Why, I can't be too sure. But fortunately hardware has come a long way & there are fewer issues like that these days.

RAM runs at whatever speed the motherboard tells it to within its advertized rating (and usually higher with good quality RAM). The CPU runs at some multiple of that (12, 12.5, 13, 13.5...) and the PCI/AGP run at a fraction (1/2, 1/3, 1/4...).

Thanks for the clarification then. The only part of that I wasn't too familiar with was the RAM issue.