Overclocking is with the dip switches block. Can go to 180 mhz according to users manual.
The hp version hardcodes to 100 or 133, regardless of the switches config, which is disappointing.
Or are you saying that does not work on the vanilla p3c-d board as well?

I patched p2b-d bios for p3-s cpus. May try it on the p3c one. But that will be the last thing in the prio list.

i though it is in the bios.
will have a look at the dip switches

edit.

asus dip switch soldered on different position, and JEN pin header is not populated.

dm- wrote on 2025-09-28, 16:48:

got this board.

no need to cut any circuit. just reflash the bios with 2x asus image.

Thank you @dm- for finding a solution. Can you explain how to reflash the bios with 2x asus image?

i moved dip switch to asus position and soldered a JPEN header.

good news: i got 150 Mhz system bus.

bad news: on the HP bios
testing shows unstability on Asus bios. when Jumperless enabled, asus bios decided it is manual. but there no valid control on the frequences, there is a list of frequences available now in bios but it is unusable.
When Jumper mode enabled, Asus bios decided it is Jumperless "auto" mode.

so i went back to HP bios and it is overclocking pretty well.

Tulli still not recognizing but i'm able to run it @ 150 mhz.

good news indeed.
i have p2b-d maxed at 150mhz fsb with full gear, so quite confident p3c-d can do that. your instabilities are probably attributed to flaky ram or cpus.
the question however is can this board reach 180mhz and especially if can do it long term stable.

with that said, i am a bit stupefied that you were able to get the hp board run at 150.
as far as i remember in my tests the 2 boards i had at the time refused to accept anything but 100 or 133.

asus bios - did you double check if the state is inverted? little hard to believe this slipped past QA.

i need resistor value near the sw1 switch.

boardview and software.

R237A must be a 0-ohm resistor, but i doubt, on the picture it does not look like 0-ohm

need a better picture near the clock gen ic ICS9248BF-77

so, i made a full clock control...

HP did static FS0-FS4 settings. so we have to unsolder one and solder another resistors and move the DIP switch.
It also looks like the IC clockgen is different. HP using ICS9248BF-77 which is 150Mhz only and frequency settings are competely different from ASUS.
And this is why Asus bios may freeze and even stop clockgen functioning.

It looks like Asus used very similar model but with additional FS pin and 180mhz support: ICS9248-97

clock table for 77 chip may be taken from datasheet pdf.

my tualatin work fine on 145mhz system bus and freezes in 3dm on 150.

Very cool. With better memory you should be able to hit 150. How your wait states look like?

What picture you need - not clear from your post.

1) area near clockgen ICS9248-97 on the original Asus P3C-D with readable resistor values
2) area near ASUS asic chip with readable resistor values.

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and one shot around the jumper 1 of the blue dip switch sw1 please.
there is a resistor just behind the dip switch.