underclocking?

[Xterraguy]

Yes, I said underclocking 🙂

My father-in-law has a 1.2 GHz (maybe 1.4, I forget) Celeron Vaio system but is considering jumping to a 2+ GHz proc instead. I would stand to inherit his current Celeron, but my MB is limited to 866 MHz (Tyan S1854, older rev.) Any problems with underclocking his proc to 866 MHz on my board? I'm currently running a Celeron 266 clocked to 533 as it is, a little more HP for free would be welcome.

Thanks,
Brent

 

[dbwillis]

I think the Celeron 1.2 is an FC-PGA2 and the Celeron 2ghz is a S478 (P4 type), you probably wont be able to get the 2ghz chip into the 1.2ghz socket...

 

[Nimbus1951]

As far as I know there are absolutely no problems in underclocking. However if your BIOS autodetects the CPU I don't know how it will behawe if it can't recognize the CPU, but if it's a jumper-board that's no problem.
I have tried to underclock before (don't ask why 😉 ) and I have never had any problems.
Btw. I'm underclocking my Memory right now and have done for a long time. It's PC-133 (133MHz) but my CPU runs only at 100 fsb and therefore the memory runs at 100 to.

Well actually I've just increased the fsb to 112 so the memory runs 112 now.... but that's a different story - and it's still underclocked 😉

Regards,
Nimbus

 

[lifeguard1999]

From the Tyan website:

"Older S1854 board revisions with marking "9900Y" or "9900YA" (next to the power supply connector, see ( image ) do NOT support P-III flip chips due to CPU change after initial board production. Older revisions will only support Pentium® III slot1 processors up to 733 MHz"

You should be able to use a Slot-T converter (see this thread) as your motherboard is listed as being compatible. You should be able to get a full 1.2 GHz, if this works.

The Slot-T converter can be had for $20 plus shipping.

 

[lifeguard1999]

After downloading the Tyan S1854 manual, I think I understand your situation better. The S1854 has both a 370 PGA socket for older Celerons and a Slot-1 for Pentium 3 chips. After Slot-1 came out, Intel reverted to a FC-PGA socket for faster Pentium 3 chips. After FC-PGA came out, Intel updated it to a FC-PGA2 socket for the 0.13 micron Pentium 3s and the 0.13 micron Celerons. You will not be able to run your FC-PGA2 0.13 micron Celeron in the PGA socket. You should still be able to run your 1.2 GHz Celeron in the Slot-1 using the Slot-T converter I mentioned in my last post.

 

[Mullzy]

I have a SLOT-T converter and a Tualatin Celeron 1.4 on order... then I found out my BX6 board is Revision 1, not 2. I've read that this combo may nuke my motherboard... so any thoughts on underclocking or under-volting? I was thinking of running at a FSB of 66 (CPU@924Mhz) or even 83 (CPU@1.1 Ghz) until I buy a new mobo.

How do you determine the voltage on an underclock? Does the Tualatin 1.4 have recommended voltages for 66Mhz and 83Mhz FSB's?

 

[lifeguard1999]

From the other thread, oldfart was able to undervolt his 1.4 GHz Tualatin to 1.3 Vcore which is down from 1.5 Vcore. The Slot-T allows voltage regulation itself (see pics in this thread) from 1.3 Vcore to 2.05 Vcore.

I do not think that undervolting will help the motherboard keep from blowing since the Slot-T is already handling the voltage.
I do not think that underclocking by reducing the FSB will help the motherboard keep from blowing.

My personal opinion is as follows:

1. Are your capacitors leaking? Or are they nice and shiny on top? If the former, then your motherboard is going to die soon no matter what you put in it.

2. Do your capacitors/mosfets run hot to the touch? Or are they nice and cool? If the former, then your motherboard may die when you stess it by overclocking it.

3. Overclocking entails risk. I buy it, I break it, its my fault. (Corollary: You buy it, you break it, its your fault.)

 

[ChampionAtTufshop]

ive been running my 1ghz tbird at 1.45v for a very long time

theres nothing wrong with undervolting/underclocking afaik...