Do you mean running the cpu at 120mhz?

In that case you would set the jumpers for a DX4-100 and run the fsb at 40mhz, no problem at all.

I run my DX4 120 at 100 with a 33mhz bus no problem

dirkmirk wrote:

Do you mean running the cpu at 120mhz?

In that case you would set the jumpers for a DX4-100 and run the fsb at 40mhz, no problem at all.

Is this de way, the original mented to be?? Or cant those board original be faster then 100 mhz?

Soupdragon wrote:

I run my DX4 120 at 100 with a 33mhz bus no problem

So i only have to set it as a 100mhz version? Then the board will it regonize it as a 120mhz one?

Robin4 wrote:

Is this de way, the original mented to be?? Or cant those board original be faster then 100 mhz? […]
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dirkmirk wrote:

Do you mean running the cpu at 120mhz?

In that case you would set the jumpers for a DX4-100 and run the fsb at 40mhz, no problem at all.

Is this de way, the original mented to be?? Or cant those board original be faster then 100 mhz?

Soupdragon wrote:

I run my DX4 120 at 100 with a 33mhz bus no problem

So i only have to set it as a 100mhz version? Then the board will it regonize it as a 120mhz one?

If your motherboard does not have support for 40MHz front side bus operation then you wont be able to get it to run at 120MHz. What motherboard/System unit do you have?

I have different 486 boards here.. But seemend they couldnt faster then the 100mhz i guess.

So the other option is only a evergreen solution or cpu powerboard to support the amd 586 -133mnz? Could that thing run the 120mhz processor aswell?

Am5x86-P75 can do 120mhz (3x40mhz) yes, and as a side-effect it will show that the processor is an AM486 instead.

ANY 486 board should be able to run a DX4-120.

Do you have model names for any of your boards so we can help you set it up?

First things first what type of socket is on your board? If its a white socket(IE socket 3) it will have no problem running the cpu.

You only need a kingston style upgrade CPU if your board is the older style with a black socket as they only provide 5 volt to the cpu, the white socket will do 3.3 volt so the cpu slots straight in but you will need a cpu heatsink/fan.

IF I can interpret what your trying to do... You know your board supports a 100mhz cpu so im assuming its a socket 3.

Set the voltage to 3.3V
Set the jumpers for a 486DX4/100
Set FSB to 40mhz

Job done, now the board may support write back cache CPUS but first things first try and get the cpu running.

Its all socket 3 boards. I have bought them from ebay..

I red some wikipedia stuff.. Its it true that intel 486 processors uses the standard 33 mhz bus? And AMD used a higher 40 mhz bus?? So there wont be are intel 120mhz 486er on the market??
I thought AMD used 33mhz bus as well. Seemed that i wrong about that one.

Robin4 wrote:

Its all socket 3 boards. I have bought them from ebay..

I red some wikipedia stuff.. Its it true that intel 486 processors uses the standard 33 mhz bus? And AMD used a higher 40 mhz bus?? So there wont be are intel 120mhz 486er on the market??
I thought AMD used 33mhz bus as well. Seemed that i wrong about that one.

Yeah Intel never released a 40MHz bus cpu they jumped straight from 33MHz to 50MHz but even that was limited to the DX50 cpu as I believe it was difficult at the time to make logic chipsets that could reliably run at 50MHz. Hence all future Intel high perfromance 486's were 33MHz bus based.

That being said i would be surprised if your socket 3 boards do not have a jumper setting for 40MHz bus operation as the AMD 486 DX40 it was a popular chip in its day.

AMD did do 33MHz bus chips but a 120MHz DX4 is a clock tripled chip, thus is requires a 40MHz bus.

Can you get any model numbers off your boards so we can see if we can find you a solution?

So, what was the main problem with getting the chipsets of the time to do a stable 50MHz? Was it a heating problem, a voltage problem, or something else entirely?

mr_bigmouth_502 wrote:

So, what was the main problem with getting the chipsets of the time to do a stable 50MHz? Was it a heating problem, a voltage problem, or something else entirely?

It was probably a combination of many factors cmos process limitations, signal quality, heat etc but definitely for VLB based motherboards 50mhz bus speed caused problems & getting more than 1 VLB card to run in a system at 50MHz was troublesome.