Overclocking a Katmai chip.

[Skeith]

I have a dual PIII Katmai 450Mhz system with 450/100/256/2.0v chips in it. (my server rig in my siggy). I recently modded the P2B-DS board to allow for a 133Mhz bus with a 1/4 PCI devider allowing for non overclocked PCI operation at 133Mhz bus speed.

However I cannot clock the chips to 133Mhz Bus. They lock into 100Mhz bus. I know its not the mod because they wont run a 133Mhz bus on the settings provided without the mod, (43mhz pci ). So I have concluded that the chips lock the bus to 100Mhz.

Is there a way to fool the chip into running 133Mhz bus. I know the celerons could be fooled by severing or covering pin b21 on the cartridge. Can something similar be done with the slot 1 PIIIs? I have flashed the bios on my board to 1014.003 (beta 3 bios).

Any Ideas or am i stuck with 100Mhz bus on these chips?

 

[Skeith]

Anyone?
Im sure somone here has overclocked a katmai in their lifetime.
Does pin b21 perform the same FSB check on pentium IIIs as it did on the celerons? I guess covering it with tape and seeing if it will post wouldent hurt, it will either work or it wont

 

[batboy]

There is a BSEL pin trick, but it's possible that those processors won't physically won't do 133 FSB, at least not without a lot more voltage and cooling.

 

[The Coolest]

Depends on the stepping you have.
My 450 Katmai ran like a champ at 133x4.5 in my MSI mobo, with stock voltage.
There are two revisions to the Katmai P3, if you have the newer one, you could squeeze quite a bit out of the chip.