Hey I read through the OC guide at the top, but i just wanted a few questions answered.

When i'm in bios, it says i can change the multiplier, but CPU-Z says it never changes. It shows 11x and my bios say 12x when i look at it. Here's a screeny of what i'm at now:


Anyways, I'm just curious as to what I should do from here. I haven't done stress tests or anything yet cuz it's late, but i'm running about 47C just with CPUZ and firefox open. So i'm guessing load i'll be about 60C, which from what i hear is about right. I want to have a 200x12 but is there any way to get it to activate? I figurd if i had a locked CPU it just wouldn't let me edit it in bios... or I could be wrong.

*EDIT* Also, I ran some prime95 tests last night and I only made it 9 minutes before it errored. I'm running at 1.75V I believe, do you guys think i should keep stepping it up or am I going to get too hot soon, and should just turn it down a few on the fsb? I kinda want that 400...

This goes back awhile so plz dbl check me but IIRC the 2500+ was multiplier locked and the 2500+ mobile was unlockable with a wire mod or conductive paint. Looks like you do not have the mobile because cpu-z shows a mobile as an xp-m. There may be more to it than this so please google 2500+ and multipliers to get the whole story.

It is not surprising that your BIOS shows the ability to change it. IIRC this option shows up in bios for some reason even though it didn't actually do anything on most cpus.

I used to have this chip and if I remember with my motherboard I had to boost the FSB with jumpers, so maybe look at your motherboard documentation first. I think you'll be getting a better result with raising the FSB rather than the multiplier with a jumper mod.

I have XP 2500+ running at 185x11 on a crappy motherboard on my work computer. It's at 1.664v. I did try the pin mod to 1.85v to see if I could push it more, but I couldn't get any more out of it. Plus it started getting kinda hot. Could be either the chip or the motherboard holding it back. Not sure. This could be the case for you too. You can try higher voltage, but you may not get any better results. Plus, the chip will run hotter and may die sooner.

I'd say keep the voltage where it is and start at FSB of 170 or so and keep raising it and testing to you hit the maximum.

I got my old 2500+ xp -M running at 204 x 11 which is about 2240 mhz. I used to have it running at 2.85 ghz stable! I could run benchmarks at 3 gig. But that was with a Prometia phase change cooler.

Anyway, as others pointed out, you can still increase the FSB to OC that Barton

What kind of cooler are you using, stock AMD? I had to get huge copper Thermalright to get stable at 2.24.

I'm using a huge copper ThermalTake hs/fan it's about a 72mm i think or somethin around there. Running it at 5100 rpm. i probably need to take it off and reseat it as i've already been using the dang thing for over 3 years now i think. But ya I'm just trying to push a little more out of it before i buy my new set. I'll try raising the voltages one more notch, if that doesn't fix it then i'll scale it down.

As I recall, early 2500XP were multiplier unlocked but later ones were locked.
With multiplier locked CPUs I believe you can still change the clock speed, but only downwards of the standard (which in your case seems to be 11)

It sounds like yours is the later type so you can only overclock with the FSB setting. So you'd need 218 x 11 to achieve 2.4GHz if your motherboard and RAM can take it.

2500XP-M (mobile) CPUs were all multiplier unlocked.