No, physically it won't break anything.

Isa especially should be unbothered as usually it's some fraction of PCI speed (or in better case it may be selectable)

PCI will likely be at 40+ mhz. It's always hard to say if this will bother some of your hardware, or the onboard IDE or any connected hard drives/ CD rom. Set it up and do a clean system install and see if you encounter any problems you hadn't encountered previously.

I don't think I've personally ever seen anything conclusively damaged by trying. If anything you will probably just get data corruption/registry errors

bertrammatrix wrote on 2025-07-16, 20:07:

No, physically it won't break anything. […]
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No, physically it won't break anything.

Isa especially should be unbothered as usually it's some fraction of PCI speed (or in better case it may be selectable)

PCI will likely be at 40+ mhz. It's always hard to say if this will bother some of your hardware, or the onboard IDE or any connected hard drives/ CD rom. Set it up and do a clean system install and see if you encounter any problems you hadn't encountered previously.

I don't think I've personally ever seen anything conclusively damaged by trying. If anything you will probably just get data corruption/registry errors

Was going to use a Voodoo 1 + Riva 128 PCI but these handle Super Socket 7 fine so I'm not sure what to think.

Nitroraptor53 wrote on 2025-07-16, 19:08:

And the 500mhz K6-2 does still support a 6x multiplier like the 400mhz one does, right?

Careful:

1) I don't think the TX has an option to disassociate the FSB from the PCI (my SiS chipset does in fact allow me to run the FSB at 83 and the PCI at 33mhz - that means to say - independent of each other). In your case, with the i430TX, running the PCI at 40Mhz is a BAD idea (read: data corruption on HDD).
2) 2x to 6x multiplier translation may not work for you at an FSB lower than 100Mhz - I say this because it didn't work for me. With the FSB set to 2x, my K6-3+ oddly boots to something like 375Mhz instead of 500Mhz. It's not a big deal, you can use something like k6init on the first line of config.sys to set the multiplier to 6.

So my theory is that 2x to 6x multiplier translation on the K6-2/3 only works when the CPU is running on a 100Mhz FSB. I'm certain that someone will correct me if I'm wrong about that.

mockingbird wrote on 2025-07-16, 21:01:

Careful: […]
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Nitroraptor53 wrote on 2025-07-16, 19:08:

And the 500mhz K6-2 does still support a 6x multiplier like the 400mhz one does, right?

Careful:

1) I don't think the TX has an option to disassociate the FSB from the PCI (my SiS chipset does in fact allow me to run the FSB at 83 and the PCI at 33mhz - that means to say - independent of each other). In your case, with the i430TX, running the PCI at 40Mhz is a BAD idea (read: data corruption on HDD).
2) 2x to 6x multiplier translation may not work for you at an FSB lower than 100Mhz - I say this because it didn't work for me. With the FSB set to 2x, my K6-3+ oddly boots to something like 375Mhz instead of 500Mhz. It's not a big deal, you can use something like k6init on the first line of config.sys to set the multiplier to 6.

So my theory is that 2x to 6x multiplier translation on the K6-2/3 only works when the CPU is running on a 100Mhz FSB. I'm certain that someone will correct me if I'm wrong about that.

The K6-2 2x to 6x multiplier works fine on a 66mhz FSB with a K6-2 400. As for the PCI speed- are you sure? The manual explicitly states that the board supports the following "external clock" speeds:
50MHz
55MHz
60MHz
66MHz
75MHz
83MHz

And it does say the ISA speed "AT Bus clock" can be chosen independently. That said, I don't see anything about PCI bus speed at all.

I feel like if it supports the 83mhz FSB at least the IDE controller should still work, and I believe that's on the PCI bus.

Nitroraptor53 wrote on 2025-07-16, 21:21:

The K6-2 2x to 6x multiplier works fine on a 66mhz FSB with a K6-2 400.

Not on my board, it doesn't (Asus SP97-XV). Again, not a big deal, it would be nice to have it say "K6-3+ 500Mhz" on bootup, but it doesn't, and it's not my BIOS (custom updated BIOS that adds support for K6-3+).

As for the PCI speed- are you sure? The manual explicitly states that the board supports the following "external clock" speeds:

Nitroraptor53 wrote on 2025-07-16, 21:22:

I feel like if it supports the 83mhz FSB at least the IDE controller should still work, and I believe that's on the PCI bus.

Yes, I'm certain you will be overclocking the PCI bus with 83Mhz on an i430TX board. See this thread, for example. This is a terrible idea. Do not run your PCI bus at 40Mhz. IDE will work, but your data will get corrupted.

And it does say the ISA speed "AT Bus clock" can be chosen independently. That said, I don't see anything about PCI bus speed at all.

AT bus clock is either referring to the KBC clock or the ISA bus clock which is not relevant. In my opinion, you are better off at 400Mhz (66mhz FSB * 6) than 75Mhz or 83Mhz.

mockingbird wrote on 2025-07-16, 21:51:

Not on my board, it doesn't (Asus SP97-XV). Again, not a big deal, it would be nice to have it say "K6-3+ 500Mhz" on bootup, bu […]
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Nitroraptor53 wrote on 2025-07-16, 21:21:

The K6-2 2x to 6x multiplier works fine on a 66mhz FSB with a K6-2 400.

Not on my board, it doesn't (Asus SP97-XV). Again, not a big deal, it would be nice to have it say "K6-3+ 500Mhz" on bootup, but it doesn't, and it's not my BIOS (custom updated BIOS that adds support for K6-3+).

As for the PCI speed- are you sure? The manual explicitly states that the board supports the following "external clock" speeds:

Nitroraptor53 wrote on 2025-07-16, 21:22:

I feel like if it supports the 83mhz FSB at least the IDE controller should still work, and I believe that's on the PCI bus.

Yes, I'm certain you will be overclocking the PCI bus with 83Mhz on an i430TX board. See this thread, for example. This is a terrible idea. Do not run your PCI bus at 40Mhz. IDE will work, but your data will get corrupted.

And it does say the ISA speed "AT Bus clock" can be chosen independently. That said, I don't see anything about PCI bus speed at all.

AT bus clock is either referring to the KBC clock or the ISA bus clock which is not relevant. In my opinion, you are better off at 400Mhz (66mhz FSB * 6) than 75Mhz or 83Mhz.

First of all, I can't read whatever thread you thought you linked to. That link appears to just lead back to this thread. I even tried to type it in manually three times and it (the website) says the page doesn't exist. Second, I have to ask WHY it would cause data loss?
If it's because the storage device cannot keep up at 41mhz, that isn't an issue. I am not using a mechanical hard disk.

I've been running a i430TX at 83Mhz FSB for ages without any data corruption on an ASUS TX97-XE, using SATA->IDE adapters and CF->IDE adapters directly connected to the internal IDE slots. The fearmongering above is overblown.

DEAT wrote on 2025-07-16, 23:38:

I've been running a i430TX at 83Mhz FSB for ages without any data corruption on an ASUS TX97-XE, using SATA->IDE adapters and CF->IDE adapters directly connected to the internal IDE slots. The fearmongering above is overblown.

Thanks for the concise response, glad it seems like that'll work. Do you, by any chance, know if my Voodoo 1 will work alright at this bus speed? Guessing not but figured I'd ask.

I ran a Voodoo 3 for a short time on my Asus TXP4 with a K6-3+ @ 500 MHz with no issues.

Hi Nitroraptor53,

That jumperless AB-TX5 board is great for a Socket 7 build, but be aware that the latest 12/03/1998-GN BIOS has some limitations.
The most obvious ones for your build are the 32GB IDE HDD limit, the 400MHz CPU speed display limit, and no Write-allocation support for AMD K6-2CXT/K6-III/K6-2+/III+ models.
Yes, all K6-2/400 and faster models (and some slower models as well) have the improved CXT core with x6 multiplier support.

A patched TX5B_J2 BIOS that fixes these limitations is available on my Unofficial K6-2+/III+ page. The link is in my signature below.

As indicated in the previous replies, a higher than 66MHz FSB exceeds the chipset and PCI specifications, because the 430TX chipset on this board uses a fixed 2/1 divider between the FSB and PCI bus clock. Normally, the PCI runs at 66/2 = 33MHz. When running at 83MHz FSB, the PCI is automatically overclocked to 83/2 = 41,5MHz. This is a 25% increase above the norm. Busmaster cards, like SCSI-Controllers or networking cards are especially sensitive to frequencies over 33MHz. But 37.5MHz (FSB 75) is usually oke.

So a 450MHz (6x75) CPU speed should be reachable without stability problems.
If 83MHz is stable on your board, you can reach 500MHz (6x83).

Cheers, Jan