Stupid question coming. I have been working on PC's for a little while, but I have never had this issue. I am upgrading a system for a friend She has a mobo with 3 DIMM slots. Currently she is running 2 sticks of 32mb of PC100. I have 2 questions. 1. Can this ram be replaced with PC133 and still run? 2. Can you have 1 stick of PC133 and 2 sticks of PC100. I have enver worked with PC100 so that is why I need your help. Thanks all.

Yes, the system will run.... However........ If the motherboard only supports PC100, then it will still use PC133 - it will just slow it down to 100 If the motherboard supports 133, then it will run fine at 133. But...... If the board supports 133, and you're using a mixture of 100 & 133, then the computer will automatically slow the 133 down so that it's all running at 100. Hope this has answered your query. P.S. See your mobo manual to find out if the board can run at 133. But if it only runs at 100, it'll still work. Regards Simon

Thanks, that is kind of what I figured but having never worked with PC100 I wanted to be sure. Thanks again

Rodius, some people have reported problems when mixing RAM of different speeds. I have never had any problems personally, but it probably depends upon the particular motherboard. I've got one Pentium 233 MMX system that has 64-MB PC66 (SIMMS), 64-MB PC100, & 128-MB PC133. Everything runs well, with no lockups, etc. Only way to know for sure is to try it. HTH Dave