View Full Version : Pc133 ram in a pc100 pentium 3 board?

10-18-2002, 10:32 AM
I've got a P3 450mhz here that takes 100mhz sd ram. I was wondering if I could use pc133 ram in it (it's cheaper than pc100). I was thinking the ram would just run at pc100? or am i wrong?

I was told it would but i'd have a very unstable system that would get BSODS often and would randomly reboot..

And while i'm at it :) Pentium 3 boards...I was told they all take pc100mhz instead of 66mhz ram. I'm sure they only use 66mhz. which is right?

Thanks for the help in advance :)

10-18-2002, 10:51 AM
SD-RAM is SD-RAM. It is backwards compatible and run at 100. THere no unstability issues at all. I was doing those kind of things for years. That's the same thing if I were to put in PC2700 instead of 2100. It would just run at the slower speed but the stick will still be there for me at that higher speed if I upgraded. Some mobo's have an option in the bios for a +33 or something like that for ram. If your doesn't then don't worry it'll run at 100. It'll probably be even cooler and less stressful on that stick of ram becuase its rated for a higher speed but not running at it.

10-18-2002, 10:54 AM
Ah thanks :) I knew i'd probably get a quick response from you :)

Also, if i'm using pc100 in a p2 pc66 board, and I increase the FSB to overclock, using pc100 ram instead of pc66 would help with stability, right??

I'm such a n00b :laugh:

10-18-2002, 10:58 AM
oh ya definitly. You'll be overclocking and not reach 100 when the stick is rated for 100. So you probably won't even have to worry about cooling the thing.

10-18-2002, 11:01 AM
Ok cool :) thanks again for all your help so far.

10-18-2002, 11:20 AM
There are some cases where the pc133 ram won't work, but in most cases it will automaticly underclock it's self.

10-18-2002, 02:34 PM
If a bios is too old to support reading SPD it will often have problems with faster ram. Yours should not be that old. I have always been able to run pc133 ram on a pc100 board. Whatever board you're talking about running at 66mz fsb though, might have problems. There is no way to tell ahead of time that I know of though.

10-19-2002, 04:59 AM
Well K6/2's are older then P3's and I ran several PC133 sticks in that board @ 100. It was flawless.

Also my brothers computer he has a duron 750 in a FIC AZ11E. And he has one stick in there running @100 and the other two are 133's. So he's running them all at 100. It runs fine.

10-19-2002, 12:19 PM
The only times that I havn't been able to run PC133 with PC100 was with a few *cough* Name Brand *cough* PC's (and PC100 with PC66 as well). :(