Celeron Tualatin Voltage Pin mod(?)

ncdesign · Post by **ncdesign** » 18.03.2006 - 23:29

Hi all, and sorry for writing in english (my german isn't good enough for
writing ;-)

I've just bought a Cel Tualatin 1300 (100MHz FSB), and a Asus TUSI-M
motherboard for a fileserver. This doesn't require much power, and therefore
I'm going to underclock/undervolt it. Unfortunately the motherboard doesn't
allow me to undervolt in the bios/via jumpers, so I've searched the net over
and over, untill i finally (and hopefully) found a solution on your pages.
However, as I mentioned earlier, my german isn't all that good, so I want to
110% sure, that I'm doing the right thing:

As I understand, according to
viewtopic.php?p=113655&sid=fb8ab5658560 ... 92762972c1
answer #4, the only thing I have to do, to lower the Vcore to 1.35V, is to
isolate "VID Pin 3" from the socket (Note: I don't use a slocket or other
things - the motherboard accepts Cel1300 Tualatin as default) - and that
this can be done simply by painting the pin with nailpolish or other
non-conductive (thin) paint?

Bonus question:

If the above is correct, and I sucessfully lower the Vcore to 1.35V, what would the effect be, if I later get a board capable of lowering the Vcore, and set it to 1.35 in the BIOS? would i then get an even lower Vcore?

Thanks in advance, and again sorry for writing in english, but i't seems,
that the Tualatin voltage experts is only to be found here ;-)

Sincerly,
Niels Hansen

ph-apoc · Post by **ph-apoc** » 19.03.2006 - 02:50

good evening .. .why do you just want to use the 1,35V Mod? I think it is more easier to modify the cpu so that it runs on 1,25. Therfore you only have to connect the vid 2 and vid 3 Pins to vss (ground).

You can use a very small cord out of an udma100-cable. I Think the CPU will work with that vcore as well (all my 1300er tualatin celeron worked down to 1,15V).

To your question. Your mod will give every Mainboard you will use in future the information "please supply me with 1,35/1,25v" so this is not depending on any bios.

Hope this did help

greets

ncdesign · Post by **ncdesign** » 19.03.2006 - 15:27

Simply because it seemed the easiest to do

And was the only 'trick' I was able to find on the net...

However your trick seems just as easy, so if I understand correctly, all I have to do is this with a small gauge wire:

Schrank21 · Post by **Schrank21** » 19.03.2006 - 20:14

Just one problem: This mod isn't possible. I did it with my own processor, but you have to calculate that the 1,45V-mod is done yet. So VID1, VID25mV and VID0 are connected and you only can do the mods that have these pins connected, too. The next lower voltage possible with the tualatin would be 1.25V (and the next one 1.05).
The mod described in the post you mentioned accords to the coppermine, not to the tualatin.

But your picture is right. I think, it would also be right to connect VID3 and VID2 only to VID25mV, this one is connected internally to the others.

Sorry for my bad English...

ncdesign · Post by **ncdesign** » 19.03.2006 - 21:28

Just one problem: This mod isn't possible

The first mod, or the one on the picture (in my second post)? (sorry if I seem a bit slow ;-)

I'm confused: You say it's possible to do the 1.25V trick, but not the 1.35? If that's right, then there's no problem - 1.25 is better than 1.35 and 1.05V is even better since I'm going to unerclock it to 858 (13*66MHz) anyway.

About the VID3, VID2 and VID25mV trick: You sure it will work? The only thing I'm concerned about is burning my CPU...
So just to make sure: There's no way to burn the CPU, by connecting the VID3, VID2 and VID25mV?

Conclusion:
The VID3 trick is impossible (isolating the VID3 pin).
The VID3, VID2 and Vss trick will give me 1.25C according to the picture?

Last question: How do i get the 1.05V you mention? which pins should I cennect?

BTW: your english is fine - I understand it ;-)
The reason I'm checking and doublechecking, is because I don't want to burn my CPU... This project is suppose to be very low cost, so I don't wanna buy a new processor, if I can avoid it ;-)

Again: thanks for your help everybody!

Regards,
Niels Hansen

Schrank21 · Post by **Schrank21** » 19.03.2006 - 23:47

The 1.35V-mod is possible. But what you get is 1.45V... My Celeron 1200 is actually running 1.45V with the 1.35V-mod. This mod doesn't have any effect when your mainboard officially supports tualatins.

I don't think that there's any possibility to burn down your CPU, the only thing you can do is starting with an extraordinary VCore... ;-) And that doesn't take much effect - I once started my pc with 2.3V, went into BIOS and saw that...

It's still running without any problems (with 1.45V).

I uploaded the complete table (found in a sheet from the Intel page... But I don't have the URL of the sheet anymore) here:

Remember: 0 means connected with VSS, 1 not connected!

As you see, the "mod already made" is 1.45V - so VID0, VID1 and VID25mV are connected to each other and to VSS...
So you can only do the mods that also connect those three pins. Those are 1.05, 1.25, 1.45 (already done), 1.65 and I think, also 1.85, but it is not printed in this table.
For example, in the table 1.25V has everywhere a 0. So each pin has to be connected to each other. VID0, 1 and 25mV are already connected, so you only have to connect 2 and 3. I think it would also be possible to connect them only to one of these four pins (1,0,25mV or VSS), but I'm not sure - so wait for more answers according to this case. The mod you made in your picture is right, I think. For 1.05V only VID2 is not connected, so it would be enough to connect VID3 to VID25mV to have 1.05...

I don't know whether you have a tB1, afair these ones have 1.5V. So it would be better if you are sure what your original VCore ist...

I'm not sure with all this. So it would be better for you and your processor to wait for more answers, though you can't burn your processor (I mentioned it before).

GrandAdmiralThrawn · Post by **GrandAdmiralThrawn** » 20.03.2006 - 09:42

I too had one of my 1400MHz P-III S boot at ~2.3V. It survived, but did not boot into Windows (i didn't initially check voltages, so i didn't see the 2.3V at first).

It seems that Tualatins have the same short-time high-voltage resistance, that coppermines had too. Wouldn't really count on that though..

ncdesign · Post by **ncdesign** » 20.03.2006 - 19:19

Just checked - I have a tB1 - atleast I think. Default Voltage printed on the CPU says 1.5V...

Schrank21 · Post by **Schrank21** » 20.03.2006 - 21:30

Hm, ok... Then there should be the 1.5V-"mod" already made, not the 1.45V... I don't know whether the things I say are right because I never read of this case, but I think it should be right.
As you see in the table, at 1.5V VID2 and VID25mV are already connected to VSS...
So the mods possible with your processor should be 1.25, 1.20, 1.15 and 1.10...

ncdesign · Post by **ncdesign** » 21.03.2006 - 20:19

Hi all, and thanks for your patience

I've checked the CPU, and the CPU/stepping says:
1300/256/100/1.5 which I guess translates to:

1300MHz, 256Kbyte cache, 100MHz FSB and Vcore 1.5V?

Stepping: SL6C7

I've been playing around with Paint Shop Pro, and I've come to this:

The above mod is confirmed!

according to the table I've made (with a little help from a tech-doc from intel

)

Anyway: If someone would check this, I would appreciate it very much!

As always, thanks in advance, and thanks for helping me!

Regards,
Niels Hansen

Schrank21 · Post by **Schrank21** » 21.03.2006 - 23:05

What you "translated" is right... ;-)
The first and the second one should be right, but the third one... Why did you connect VID1? I would like to test it, but my Celeron hasn't 1.5 and so I can't do them/they would give other voltages...

ncdesign · Post by **ncdesign** » 22.03.2006 - 17:06

To change the status of VID1 from 'off' to 'on'.
As I read the table from Intel, I need all VID-pins connected to get 1.25V (I could be wrong however)...

Schrank21 · Post by **Schrank21** » 22.03.2006 - 22:18

Uhrg, sorry... I meant the second one, the third one should be right so far...

ncdesign · Post by **ncdesign** » 23.03.2006 - 21:39

You're right - that is an error. VID0 and VID3 should be connected to ground (Vss) right?

ncdesign · Post by **ncdesign** » 27.03.2006 - 16:34

...Anybody... Help..?