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Alpha P3125S Installation Tips Please?

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May 29, 2001
Hey folks,

I just received my new Alpha 3125S for my Slot 1 and I am preparing to obtain the elusive 1 gig overclock with my PIII-750.

I have a couple questions about installing this thing for the best overclock and just want to make sure I get it right.

First of all, do you recommend I lap the heatsink? And if so, how much and with what type of sandpaper? I have seen varied results, would like some other opinions.

Also, I have a tube of Arctic Silver that I plan to apply to just the center square of the PIII chip. Is that enough or am I missing something? And the best bet is just to apply a very small thin layer on that, right?

Any other suggestions or even confirmations on what I said above would be most appreciated! I'll return with results later.


Another quick question..

Should I remove the backplate off of the P3 chip. I have seen a few articles that suggest you get even better temps with the back plate removed.

Any thoughts?

Brad, The 3125 is a nice heatsink,

"First of all, do you recommend I lap the heatsink? And if so, how much and with what type of sandpaper? I have seen varied results, would like some other opinions."

Probably lapping is not necessary as Alpha takes great pride in thier heatsinks and the area where the CPU die makes contact and is probably as flat as its going to get.
Regarding removing the back plate, thats a pretty good idea to do so as the temp with it on is roughly 5* higher than without, hey try it both ways, Just make sure you affix the Alpha securely as you dont want the heatsink to fall out of the slot as it could break your Video card. It weighs over a pound if memory serves me correct.
Yes the 3125 is very nice, im very happy with mine :)

I lapped mine and didnt notice any major differencre, it was flat for the most part out of the box, I just wanted to remove the small machine ridges that were left. I went up to 1500 grit.

Use a businesss card or something similar to apply a thin coat of AC to just the die, thats all thats needed.

I dont have much to say about the backplate removal, execpt for, have you done it? and,what were the temp changes?
Well, I seem to have hit a wall at 930! I can't get this thing to post past 124 fsb for some reason! I'm using an Asus P3v4x motherboard. Any ideas? Would a burn-in help? I can only run as high as 124/31 now. Neither of the 133 fsb options will work. Also, would changing SDAM Config or System/SDRAM Frequency Ratio help?

I am doing this all through the BIOS by the way. If there are any manual jumpers I could set to get it working better, I would appreciate knowing that as well!

CPU Vcore is currently at 1.80 and I don't think I should go much higher...Should I?

She's running cool at 31c according to Asus's BIOS, but we know this is usually about 10c too high, so I suppose I'm around 21c at the moment.


do you know the stepping of your chip?

is your memory generic or brand name? if your memory settings are 3-3-3-6 that all you can do there...how many sticks of memory do you have? I had trouble running 2 generic sticks...try moving the sticks into different slots, that worked on my corsair.
I left my ratio on auto
A burn in may or may not help, id would hold of on that for now

what do you have for cards? have you tryed removing any?

as a personal rule I wont go over a .3v increase on any cpu.
I seem to recall reading some posts around here regarding that motherboard. Had to do with people upgrading the BIOS, and the newer version didn't overclock as well. I can't recall the BIOS version as I don't have one of these, but I'm wondering if you might have this version installed. I'd think that chip would do quite a bit better than that. I really can't believe you've hit the wall already.

Check the "intel Motherboards" topic for post concerning this mb....this might have something to do with it (or might not)

I've got the P3125 on my P///. Does work extremely well IMHO. What fans are on yours?? 60x60x25 YS Techs?? That's what I've got, and my load temps never hit 40c....

As far as upping the vcore setting from 1.8v....I'm at 1.95v, BUT (!!), I'm extremely sure of my temps being exactly or w/in 1 or 2c of what the Asus Probe says it is. I'm usually idling at around 22c, and as I said, never hit 40c under load. Could you go higher, sure, and you might need to. Just make sure of those temps being nice and low and steady before you do.

You mention 31c above....I'm assuming by the way you refer to it that's your idle temp. That's high. You did put the "feet" on the hsf right? The Alpha is sitting nice and level on the cpu die? Your absolutely sure that the Asus Probe is 10c off? Definitely make sure of this before you up the vcore setting.

Mr B