To expand on the above suggestion

1-2=0, 2-3=1

0,0,0
1,0,0
0,1,0
1,1,0
0,0,1
1,0,1
0,1,1
1,1,1

Your combos^
Count in binary

(Solved) Cyrix 400gp/366gp multiplier settings

Another thread where this was done.

I’ve used this to discover hidden fsb settings also. The coolest socket 7 motherboard that you’ve never heard of

Sphere478 wrote on 2022-03-12, 18:01:

What cpu is it? What are the letters of the model? Example “k6-2+ 570acz” […]
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TOMMY_THE_DOG wrote on 2022-03-12, 16:49:

That got it to 550MHz! Woohoo! Mission accomplished! Thank you so much everyone. I got this CPU for $12, so it is a good upgr […]
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Doornkaat wrote on 2022-03-12, 06:22:

From the table we can extrapolate that J14=BF1 and that 1-2=BF signal high (corresponding jumper open on most motherboards) /2-3 […]
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From the table we can extrapolate that J14=BF1 and that 1-2=BF signal high (corresponding jumper open on most motherboards) /2-3=BF signal low (corresponding jumper closed on most motherboards).
As soon as we know all three BF jumpers we can set any multiplier supported by the K6-2.
To figure out the other two BF jumpers please set the jumpers as follows:
Multiplier: J14 2-3 / J15 2-3 / J16 1-2.
FSB: J8 2-3 / J9 2-3 / J10 1-2 / J11 1-2 / J12 1-2. (100MHz)
If it posts at 250MHz we know J15=BF0 and J16=BF2.
If it posts at 500MHz we know J16=BF0 and J15=BF2.
If it does something else my conclusions are probably wrong. 😄

That got it to 550MHz! Woohoo! Mission accomplished! Thank you so much everyone.
I got this CPU for $12, so it is a good upgrade! I know that the plus models are a bit better, but for a system with no AGP slot, I don't think the upgrade would be worth it for me in this machine. Thank you again.

I imagine that a CPU nominally rated at 533MHz will be fine at 550. My FSB is still at 100MHz.

What cpu is it? What are the letters of the model? Example “k6-2+ 570acz”

Yeah, 550 is probably fine for a 533

Do stability testing to confirm it’s stable, may need a 0.1v bump

Speaking of, you should check your voltage

A resistor leg in the middle pin on the notched corner side of the cpu to ground with a volt meter is the easiest way to test. Close the lever.0803944D-90A0-4AB3-B1A6-021A2185934C.jpeg

Btw, what setting did you use? What mobo is it? We could document it on ultimate retro if you can provide more infos

Edit: reading further,
Try the next fsb setting (95mhz if you have it) but before you do that, confirm voltage the 550 uses .1v more than the 533

It is not stable I am realizing. I will bring the FSB down to 95 and see what is up. There is a set of voltage jumpers, but the manual that I have cut the information on those out.

The CPU model is "K6-2/533AFX" The CPU top specifies 2.2v core voltage, 3.3v I/O . Just like the CPU that it replaced.

The motherboard is a Compaq original. I think it was manufactured by Mitac, but I cannot be sure. It has a SiS530 chipset and uses three small molex-ish connectors on different spots of the motherboard to provide power from the PSU. I took some photos that I will soon upload. "UZI" is printed clearly in big letters between the first PCI slot and the northbridge. There is an integrated ESS-Solo1 soundcard. It kicks ass. Integrated SiS GPU on an internal AGP2x bus. Three PCI slots, 1 ISA slot. 3 PC100 SIMM slots. I am booting from an IDE to SD card interface, having removed the stock 5 inch HDD entirely.

TOMMY_THE_DOG wrote on 2022-03-12, 22:58:

It is not stable I am realizing. I will bring the FSB down to 95 and see what is up. There is a set of voltage jumpers, but th […]
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Sphere478 wrote on 2022-03-12, 18:01:

What cpu is it? What are the letters of the model? Example “k6-2+ 570acz” […]
Show full quote

TOMMY_THE_DOG wrote on 2022-03-12, 16:49:

That got it to 550MHz! Woohoo! Mission accomplished! Thank you so much everyone.
I got this CPU for $12, so it is a good upgrade! I know that the plus models are a bit better, but for a system with no AGP slot, I don't think the upgrade would be worth it for me in this machine. Thank you again.

I imagine that a CPU nominally rated at 533MHz will be fine at 550. My FSB is still at 100MHz.

What cpu is it? What are the letters of the model? Example “k6-2+ 570acz”

Yeah, 550 is probably fine for a 533

Do stability testing to confirm it’s stable, may need a 0.1v bump

Speaking of, you should check your voltage

A resistor leg in the middle pin on the notched corner side of the cpu to ground with a volt meter is the easiest way to test. Close the lever.0803944D-90A0-4AB3-B1A6-021A2185934C.jpeg

Btw, what setting did you use? What mobo is it? We could document it on ultimate retro if you can provide more infos

Edit: reading further,
Try the next fsb setting (95mhz if you have it) but before you do that, confirm voltage the 550 uses .1v more than the 533

It is not stable I am realizing. I will bring the FSB down to 95 and see what is up. There is a set of voltage jumpers, but the manual that I have cut the information on those out.

The CPU model is "K6-2/533AFX" The CPU top specifies 2.2v core voltage, 3.3v I/O . Just like the CPU that it replaced.

The motherboard is a Compaq original. I think it was manufactured by Mitac, but I cannot be sure. It has a SiS530 chipset and uses three small molex-ish connectors on different spots of the motherboard to provide power from the PSU. I took some photos that I will soon upload. "UZI" is printed clearly in big letters between the first PCI slot and the northbridge. There is an integrated ESS-Solo1 soundcard. It kicks ass. Integrated SiS GPU on an internal AGP2x bus. Three PCI slots, 1 ISA slot. 3 PC100 SIMM slots. I am booting from an IDE to SD card interface, having removed the stock 5 inch HDD entirely.

We could help you a lot better with high res pics of front and back of your board. Not only that, we can upload it to help others.

Give it 2.3v it won’t hurt it. (If you know how) have you checked the voltage like I was saying?

So 533afx, you have the same cpu that I have from my earlier pic.

I showed the 550mhz part was 2.3v if you didn’t catch that. I suspect there is very little difference between these models other than .1v and 17mhz

Btw, this model cpu (the 533) was intended for a 97mhz fsb. But I honestly don’t recall many mobos supporting that.

Not that it matters, you can basically set the fsb to whatever you want and the cpu won’t care as long as you choose an appropriate multiplier.

I like the 5.5x95 or 5.5x100 options best for you.
2.3v is no biggie.

The standard wisdom is to get a new system running stable at stock settings first, before experimenting with all different settings and changes. But of course for this scenario, not all motherboards are going to offer a 97Mhz bus speed.

Therefore, I would probably look to a simple (and slightly underclocked) 5x100 setup first. And ensure full stability under all usage scenarios, with that.

I'm not sure what information you are looking for on the motherboard. I took some photos just now when I opened it up to bring the FSB to 95 MHz. Now the BIOS is reporting an FSB of 95 with a CPU speed of 500. CPU-Z say that the FSB is 95 and the CPU is at 524MHz.

If you give me more specific instructions, I can get better photographs.

Shreddoc wrote on 2022-03-12, 23:14:

Standard wisdom is to get a new system running stable at stock settings first, before experimenting with all different settings and changes.

I added more to above post,

This cpu was intended for 97mhz fsb 533 is a really odd cpu speed.

Not many mobos that I have encountered have had the 97mhz option, it’s usually 100, 95, 83, 75, 66.

But anyway, unless he has a 97mhz option setting it to “stock” won’t be possible but 95x5.5 and 100x5.5 are really close. The next model cpu (550) bumps the voltage .1v using the same core, so I suspect if he does that there is a pretty good chance he can make it work at 550.

But, if not 95x5.5 is the next option (assuming they don’t have 97fsb)

Btw, voltage settings are usually like this:

Find your voltage block

Sw0 + 0.1v (this on others off is usually 2.1v setting)
Sw1 + 0.2v (this and sw0 on is usually 2.3v)
Sw2 + 0.4v
Sw3 + 0.8v (others off, this one on is usually 2.8v setting)

Shreddoc wrote on 2022-03-12, 23:14:

Standard wisdom is to get a new system running stable at stock settings first, before experimenting with all different settings and changes.

In that vein, I'm slightly concerned at some of the arbitrary mucking around here - when it seems, from the thread history, that the thing has never really been given a stock setup yet - so personally I would instead be putting focus there first.

Then, if you afterwards make changes and find instability, you have the stock experience to compare with.

I am not sure what you mean by a "stock setup", but I have been using this system for a few weeks with the stock 380MHz CPU. I'm running Win98SE, and playing Age of Empires, Star Trek 25th, and Duke 3D, to name a few titles. The system was rock solid stable before I upgraded, and the upgraded CPU was super-stable at 400MHz.

TOMMY_THE_DOG wrote on 2022-03-12, 23:20:

I'm not sure what information you are looking for on the motherboard. I took some photos just now when I opened it up to bring the FSB to 95 MHz. Now the BIOS is reporting an FSB of 95 with a CPU speed of 500. CPU-Z say that the FSB is 95 and the CPU is at 524MHz.

If you give me more specific instructions, I can get better photographs.

Okay, let’s see if we can find your board based on those, there is usually a model number between the pci slots if you see that let us know.

Your new settings sound good and cpuz mhz and bios report is okay. (Bios rounds up or down) cpuz is real speed

Edit: I don’t see anything between the slots.

FWIW, Jazz Jackrabbit is working now without throwing the runtime 200 error. Also there is no information printed between the expansion slots on this board.

TOMMY_THE_DOG wrote on 2022-03-12, 23:23:

Shreddoc wrote on 2022-03-12, 23:14:

Standard wisdom is to get a new system running stable at stock settings first, before experimenting with all different settings and changes.

In that vein, I'm slightly concerned at some of the arbitrary mucking around here - when it seems, from the thread history, that the thing has never really been given a stock setup yet - so personally I would instead be putting focus there first.

Then, if you afterwards make changes and find instability, you have the stock experience to compare with.

I am not sure what you mean by a "stock setup", but I have been using this system for a few weeks with the stock 380MHz CPU. I'm running Win98SE, and playing Age of Empires, Star Trek 25th, and Duke 3D, to name a few titles. The system was rock solid stable before I upgraded, and the upgraded CPU was super-stable at 400MHz.

Sorry, I edited that post, as I found it hard to make my point effectively.

What I mean is, it's a 533Mhz CPU, so it should be tested at 533Mhz, or if not possible due to motherboard settings, then slightly under - as close as possible. e.g. 5 x 100, or even better (as suggested by Sphere), 5.5 x 95 if motherboard allows.

So you have a stability baseline for that CPU. Against which you can compare any future overclocks or settings experiments.

Otherwise, it might be a faulty CPU, and you would never know. You might see instability at this-or-that-other setting, and never know if it's because of the overclock, or just because the stock CPU itself is faulty.

Shreddoc wrote on 2022-03-12, 23:29:

Sorry, I edited that post, as I found it hard to make my point effectively. […]
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TOMMY_THE_DOG wrote on 2022-03-12, 23:23:

Shreddoc wrote on 2022-03-12, 23:14:

Standard wisdom is to get a new system running stable at stock settings first, before experimenting with all different settings and changes.

In that vein, I'm slightly concerned at some of the arbitrary mucking around here - when it seems, from the thread history, that the thing has never really been given a stock setup yet - so personally I would instead be putting focus there first.

Then, if you afterwards make changes and find instability, you have the stock experience to compare with.

I am not sure what you mean by a "stock setup", but I have been using this system for a few weeks with the stock 380MHz CPU. I'm running Win98SE, and playing Age of Empires, Star Trek 25th, and Duke 3D, to name a few titles. The system was rock solid stable before I upgraded, and the upgraded CPU was super-stable at 400MHz.

Sorry, I edited that post, as I found it hard to make my point effectively.

What I mean is, it's a 533Mhz CPU, so it should be tested at 533Mhz, or if not possible due to motherboard settings, then slightly under - as close as possible. e.g. 5 x 100, or even better (as suggested by Sphere), 5.5 x 95 if motherboard allows.

So you have a stability baseline for that CPU. Against which you can compare any future overclocks or settings experiments.

I am now running at 5.5 x 95. Things are better so far. No random errors from Windows, no Turbo Pascal runtime error. I am still testing this new configuration. It might be where I leave things. I bought a 533MHz CPU. 524MHz is perfectly acceptable.

TOMMY_THE_DOG wrote on 2022-03-12, 23:31:

Shreddoc wrote on 2022-03-12, 23:29:

Sorry, I edited that post, as I found it hard to make my point effectively. […]
Show full quote

TOMMY_THE_DOG wrote on 2022-03-12, 23:23:

I am not sure what you mean by a "stock setup", but I have been using this system for a few weeks with the stock 380MHz CPU. I'm running Win98SE, and playing Age of Empires, Star Trek 25th, and Duke 3D, to name a few titles. The system was rock solid stable before I upgraded, and the upgraded CPU was super-stable at 400MHz.

Sorry, I edited that post, as I found it hard to make my point effectively.

What I mean is, it's a 533Mhz CPU, so it should be tested at 533Mhz, or if not possible due to motherboard settings, then slightly under - as close as possible. e.g. 5 x 100, or even better (as suggested by Sphere), 5.5 x 95 if motherboard allows.

So you have a stability baseline for that CPU. Against which you can compare any future overclocks or settings experiments.

I am now running at 5.5 x 95. Things are better so far. No random errors from Windows, no Turbo Pascal runtime error. I am still testing this new configuration. It might be where I leave things. I bought a 533MHz CPU. 524MHz is perfectly acceptable.

That is good. That is where I would leave it, personally.

Other considerations/options:

• You can use setmul to enable/disable L1 cache for K6/2, which gives some slowdown, helps for some things.
• Or you can temporarily clock down on the motherboard, say for a week, if you want to spend a time playing games which require it.
• There is the physical switch option as I demonstrated
• There is your original option of (when you can afford it) obtaining a + CPU

Does this look correct?

https://www.ebay.com/itm/324617657352?hash=it … VwAAOSw-tdgmoXq

More pics

I think I found your voltage settings,

Here are some higher res pics

Yeah, that's my motherboard

TOMMY_THE_DOG wrote on 2022-03-12, 23:56:

Yeah, that's my motherboard

it appears the info is hidden under the 5 1/2” drive bays

Including the multi settings

You're saying I need to pull the CD-ROM drive, and there will be information printed on the case underneath?

TOMMY_THE_DOG wrote on 2022-03-13, 00:15:

You're saying I need to pull the CD-ROM drive, and there will be information printed on the case underneath?

May be easier to pull the mobo.

Get us some high res shots of front and back, so the next guy can have the info also 😀

I wasn’t able to find your mobo on ultimate retro so we can make a page for it and document all the settings.

Sphere478 wrote on 2022-03-13, 00:17:

May be easier to pull the mobo. […]
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TOMMY_THE_DOG wrote on 2022-03-13, 00:15:

You're saying I need to pull the CD-ROM drive, and there will be information printed on the case underneath?

May be easier to pull the mobo.

Get us some high res shots of front and back, so the next guy can have the info also 😀

I wasn’t able to find your mobo on ultimate retro so we can make a page for it and document all the settings.

Man, pulling the motherboard would be a gigantic pain in the ass. Same with getting to its back side. It would be way easier to pull the cdrom