Welcome to the Forum! 😀
Klamath Pentium II have a TDP of 43W at 2.8V and Katmai Pentium III have a TDP of 34.5W at ~2.1V.
I wouldn't worry about the 1GHz Coppermine Pentium III's 29W at 1.75V on a board like the BH6 (1.02) that's designed for overclocking. Especially since Rev. 1.02 is 100% meant to run Coppermine CPUs.
I don't know who comes up with that stuff any why.

You should consider recapping the board though.

Doornkaat wrote on 2021-03-29, 18:23:

Welcome to the Forum! :-) Klamath Pentium II have a TDP of 43W at 2.8V and Katmai Pentium III have a TDP of 34.5W at ~2.1V. I w […]
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Welcome to the Forum! 😀
Klamath Pentium II have a TDP of 43W at 2.8V and Katmai Pentium III have a TDP of 34.5W at ~2.1V.
I wouldn't worry about the 1GHz Coppermine Pentium III's 29W at 1.75V on a board like the BH6 (1.02) that's designed for overclocking. Especially since Rev. 1.02 is 100% meant to run Coppermine CPUs.
I don't know who comes up with that stuff any why.

You should consider recapping the board though.

Hi Doornkaat,

Thank you for the welcome! 😁

I'm definitely considering recapping. Can't really trust 20 year old caps, especially on a board I don't know the history of. Bought it used on eBay. So far I have only tested it to boot into BIOS and flashed it with the SS BIOS. I even swapped in my original 300A just to do that. The board overall looks to be in good condition and came with a 450MHz P3.

I think the issues for the VRM probably came from the Tualatins needing more current. The TDPs don't tell much since peak currents for the Klamath and Katmai cores actually peak around 14.2A and 16.1A according to Intel data sheets for the VRM 8.1 and VRM 8.2 Spec.

The Coppermine 1GHz P3 peaks at 20.2A which is close to the 20.6A + being pulled from Tualatins. I'd assume it probably will be okay since the board was designed for overclocking. Although Abit never officially said the BH6 could support the Coppermines on the 1.0x revisions. I don't plan on overclocking anyways unless I decide to push the FSB to 112. I'm more likely to attempt to undervolt it to try to lower the load on the VRM.

Sorry, I was stupid.😅
I confused Rev 1.2 with 1.02. Now I understand the concern.
Reevaluation:
While the VRM isn't officially specced for Coppermine CPUs/VRM 8.4 I believe the BH6 meets Intel VRM 8.2 DC-DC Converter Design Guidelines that require 20A Icc core since those are required in the April 1998 Intel 440BX AGPset Design Guide. Again, given it's an overclocking board from Abit's heyday I will assume it exceeds those requirements.
VRM 8.4 also specified more CPUs and tighter tolerances which I believe the better slotkets (even without full VRM) ensured, so ymmv with 'native' Slot 1 Coppermines. A good VRM design again may meet VRM 8.4 requirements even though being targeted at 8.2.
Also Intel VRM 8.4 DC-DC Converter Design Guidelines, Table 1, Note 4. describes how a good VRM design may reduce Icc core max of a 1GHz Pentium III to 19A.
I do realise that TDP is not equal to chips' (peak) power consumption but I believe comparing TDP (relative to voltage) gives a reasonable approximation of continuous thermal stress on voltage regulation circuitry. (Though not factoring in peaks that would probably cause system instability long before increased wear.)

I hope this answer is more helpful though of course it is a lot of guesses based on the assumption Abit made good design choices. Shortcomings in tolerances required by VRM 8.4 but not 8.2 should affect system stability more than longevity with the high end Coppermines imho, so if the system runs stable you're probably fine.

Is it relevant for the issue that the 55N03LT MOSFETs mentioned in the first post are rated for 55A as opposed to 19A ?

PARKE wrote on 2021-03-30, 14:39:

Is it relevant for the issue that the 55N03LT MOSFETs mentioned in the first post are rated for 55A as opposed to 19A ?

In a switching converter this number is less significant than in a linear regulator (the kind you'd typically find on earlier Socket7 boards and older).

Doornkaat wrote on 2021-03-30, 09:30:

Sorry, I was stupid.😅 I confused Rev 1.2 with 1.02. Now I understand the concern. Reevaluation: While the VRM isn't officially s […]
Show full quote

Sorry, I was stupid.😅
I confused Rev 1.2 with 1.02. Now I understand the concern.
Reevaluation:
While the VRM isn't officially specced for Coppermine CPUs/VRM 8.4 I believe the BH6 meets Intel VRM 8.2 DC-DC Converter Design Guidelines that require 20A Icc core since those are required in the April 1998 Intel 440BX AGPset Design Guide. Again, given it's an overclocking board from Abit's heyday I will assume it exceeds those requirements.
VRM 8.4 also specified more CPUs and tighter tolerances which I believe the better slotkets (even without full VRM) ensured, so ymmv with 'native' Slot 1 Coppermines. A good VRM design again may meet VRM 8.4 requirements even though being targeted at 8.2.
Also Intel VRM 8.4 DC-DC Converter Design Guidelines, Table 1, Note 4. describes how a good VRM design may reduce Icc core max of a 1GHz Pentium III to 19A.
I do realise that TDP is not equal to chips' (peak) power consumption but I believe comparing TDP (relative to voltage) gives a reasonable approximation of continuous thermal stress on voltage regulation circuitry. (Though not factoring in peaks that would probably cause system instability long before increased wear.)

I hope this answer is more helpful though of course it is a lot of guesses based on the assumption Abit made good design choices. Shortcomings in tolerances required by VRM 8.4 but not 8.2 should affect system stability more than longevity with the high end Coppermines imho, so if the system runs stable you're probably fine.

Thank you for that information. I was aware of the Icc core reduction for 19A.
Although I didn't know about the 20A Icc core modification spec within the April 1998 Intel 440BX AGPset Design Guide. That is quite interesting.

I guess the BH6 will be okay.

I did notice the slew rate for FC-PGA within the VRM 8.4 spec is 240A/μs. I'm assuming that was supposed to be 24A/μs, since VRM 8.5 specs it for 23A/μs peaking slightly below 24A/μs.
I'm assuming that small change in slew rate isn't a problem, considering I used a celeron coppermine 900 on my original BH6 for over 5 years which was subject to the same higher slew rate.

Is there any specific series that is best for capacitors to use to replace on the VRM? I was thinking of buying general purpose Nichicon caps from Mouser. My local shop usually stocks Rubycon and KZG but they've been having stock issues for months.

I have attached a few things I noticed on the board below.

The board indicates revision 0.5 for the PCB (I read on a google groups post that 0.5 or above is okay for coppermine? At least according to a post made by Abit Support.)
Also I assume that says the 11th week of 1999, since the sales tag says June 24, 1999

Interesting to see such a simple VRM considering how different they are nowaways

Back in time, I had BH6/BF6 which ran with a clocked slot 933 coppermine, overvolted at around 1060MHz and stable over years (under continuous load); that said, the caps needed replacing around 2003, so which i'm sure it'll handle it, maybe it contributed to that, but I don't see there being any prima facie issue with plugging it in and trying.

nitrile wrote on 2021-03-31, 07:00:

Back in time, I had BH6/BF6 which ran with a clocked slot 933 coppermine, overvolted at around 1060MHz and stable over years (under continuous load); that said, the caps needed replacing around 2003, so which i'm sure it'll handle it, maybe it contributed to that, but I don't see there being any prima facie issue with plugging it in and trying.

Thank you for the input. What revision was your BH6? For the BF6, the VRM was designed for Coppermine.

I think I had my original BH6 until around a few years ago with the Celeron 900 and it had all the original caps without a single one blowing.
Although realistically I wouldn't be surprised if they had leaked a bit on their bottom sides.

I'll probably give it a whirl soon. I'm still waiting on a few parts for the build to arrive in the mail.

So long time no update.

But I've since recapped the BH6. I ended up using general purpose caps 🙁 crap G-Luxon caps cause that's all I could get at my local store. But for the VRM I used specially ordered Panasonic caps from Digikey. I'll have to do more testing on it though since my board doesn't seem to be happy with more than 512mb of ram. I've also been running it with a Powerleap. I suspect my revision is probably okay with the SL5QV. At some point in the summer I'm probably going to play around with the SL5QV on an ABIT Slotket !!! (auto voltage detect doesn't work for some reason). Currently I'm running the powerleap with a tualeron 1400.