Removing multiplier lock on PII 350. How?!?!

[cchuck]

Hi,
Apologies for the off topic post, but I seem to remember that someone on these message boards managed to remove the mutliplier lock on their PII 350. Can they or someone else who knows, please explain the procedure for doing this?

I'm at my wit's end because I cannot find any resources for this on the web, and the responses in newsgroups have generally expressed the opinion that it cannot be done. But I think it can!!

Thanks in anticipation,

[Rags]

Sure, all you have to do is tape pin B21. If this doesn't work, then you have a later P2 350 that can't be unlocked this way.

Rags

[Rags]

Oh, and if you have an ABit BH6, BX6r2, BE6, BP6, BF6,or BE6r2, then you will have the option to instead make it "low" in the bios.

Rags

[Kruzin]

It can be done....on certain 350s. I can't remember the exact ones, but like Rags said, taping pin b21 is the way to do it. I ran my 350 at 412 (103fsb*4) for a long time...try it, and if it works, it works...if it don't, well ya tried

[cchuck]

Cool thanks guys, I will try it.
I was confused, because I thought the effect of taping B21 was to enable 66Mhz CPUs to run at 100Mhz on BX boards. I wasn't sure of its purpose on PII 350s and above.

BTW, The reason I want to o/c it is because my c300a, which I had high hopes for, will only go to 450. If my PII 350 can't beat that, then I'm going to try 2.2 volts and see how far these puppies will go.

What do you recommend I use for taping the pins?

[Rags]

You are correct, B21 controls the automatic detection of the 66 or 100 fsb, but with the P2 350, it was found that on some you could unlock the multiplier by taping the pin off, which was an anomalie that was fixed eventually by Intel. What kind of motherboard do you have? Some other non ABit boards have this option in the bios.

Rags

[Frank]

Yes, Abit boards offer the 'SEL 100/66# Signal' option.
This will only work with PII350's or 400's manufactured before August '98, when Intel applied the cpu multiplier lock that defeated Abits boards (bastards ).

[cchuck]

Yeah kickass!!

I got my PII350 in about July/August 1998, so it was probably at least a few weeks old by the time I got it. It's Malay SL2S6 98130669-1152. Not sure which no. represents the week of manufacture.

BTW, my mobo is an Asus P2B. As far as I'm aware there is no upgrade to the bios which allows you to select 66/100 like the Abit boards. It's a good board though, but my main complaint is that there simply aren't enough intermediary bus speed settings, and the pci dividers are very poor. After 100Mhz, you have to go all the way to 133 to get the pci back to 33 Mhz. Having said that, I ran the PII 350 @ 392 (x112Mhz) for a year, and got no adverse effects from the 37Mhz PCI bus.

BTW, is a standard PII heatsink / fan enough to be running the chip at 460Mhz (if it gets that far)? And what if I upped the voltage to 2.2?

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[Rags]

The only way to tell is to try. These chips have been found to be very overclockable. Use some teflon tape to tape the pin and you are set.

Rags

[Mark F]

cchuck,
If I read that right your chip is from the begining of April '98. There is another kind of PII besides locked or unlocked. Some were max multiplier locked. You could change the multiplier down, but not up. I hade a PII-400 like that.

Mark F.

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OH NO, my retractable cup holder swallowed a CD

[UncleJoe]

Well... Is there anybody out there, who knows
is it possible remove celerys (ppga 400@500 on Abit slot1-adapter ) multiplier ? If it is, how could it be done ?? It would be much nicer to run it 5X100 than 6X83.

Jouni

[Rags]

Sorry, no way currently to disable the multiplier lock on the celery, or any other Intel P2/P3 after these.

Rags

[Frank]

Yeah, someone actually took the cpu slug off a PII333 and put it on the board of a PII300 and it ran at 333. Also put the cpu slug of the PII300 onto the board of the PII333 and it ran at (surprise surprise) 300.
Basically proving that the cpu multiplier lock was in the cpu slug and not on the cpu board. This probably applies to celerons too.
I think it was ARS Technica or Anandtech or something like that.

[Frank]

well Steve, the PII333 runs at 112FSB giving me 560. But the point I was trying to make was to UncleJoe in that it is so far not possible to change the cpu multiplier lock on the Celerons since the lock is within the slug.
Sorry UncaJoe.

[Frank]

However, interestingly enough I read a review some time ago of a mobo supporting dual celerons.
They used a C400 and C500 (something like that). What happened was the C500 automatically scaled down to run at the same speed as the C400!
ie. changing it's cpu multiplier to conform with the C400 multiplier.
Thought that was interesting.