In my experience very few 586s will do 160MHz at 3.3V. Most will run at 4V and sometimes you'll find one that only runs at stock frequency.

My AMD Am5x86 happily runs Windows NT x32 Workstation V4.00 Build 1381 Service Pack 6a @ 160 MHz with the voltage @ 3.45 volts as specified on the package. What voltage have you set?

With my DEC Venturis 4 motherboard I can dynamically change the FSB speed between 25, 33 and 40 MHz and the system keeps working.

I left the CPU voltages alone at Default what ever the CPU label recommends.
I only changes the Bus speed on the motherboard to 4x40mhz which equals 160mhz.
My computer runs fine at this speed. Very stable.
Running Win95

As I'm nowhere near as talented as feipoa at soldering, when I've messed around with doing an Am5x86-160, I end up soldering another resistor in parallel on the underside of the board where the resistor controlling the voltage regulator is. If you look up the datasheet for it, there should be a formula in there to at least hint at what value to use. Then you can test using a voltmeter before putting the CPU back in.

As these take 3.45V +/- 0.15V, if you can manage it at 3.6V (worked for me I think, or maybe 3.68V) you're technically still in-spec.

I've just left the voltage at the default 3V position according to the manual of each board. (The jumper was already set that way and I checked it but didn't change it)

For the 5486AL board, it's just one jumper to set between 3V, 4V and 5V.

On the 486AM /s board, it has JP22 and JP23 where JP22 can be configured but JP23 is missing, (You can see JP23 on the left edge of the pic I uploaded)

I was concerned that 4V would be too high, so I haven't tried that yet.

4v setting would beslightly higher than specs whould suggest but with decent cooling and case air flow it can run fine.
If the 160MHz would be too much for the 586, you may try it in DX4 mode: multiplier set to 3x and bus to 50. This is where my 5x86 feels fine, but at 4x40 it freezes the system, even with all timings loosened maximum...
That is, if the graphics card supports PCI at 50MHz or the boards had the 2/3 divider ofc.

I set the voltage to 4V and now it boots and seems stable.

brotherdg2@gmail.com wrote on 2025-04-04, 21:48:

In my experience very few 586s will do 160MHz at 3.3V. Most will run at 4V and sometimes you'll find one that only runs at stock frequency.

Yeah, I have a pile I kept that could show some "stability" at like 180MHz/4V or something like that (at least a Quake timedemo but there were better SKUs too), and it was already a higher bin than 160/3.45V. Then I got hold of a board that couldn't do 3.45V and at its default 3.3V even some of those failed.

4 V for AMD Am5x86-P75 X5-133ADW seems too much to me.

ADZ CPUs can work up to 85 °C, but ADW chips are limited to maximum of 55 °C. So ADW CPUs can withstand far less overvoltage and overclocking than ADZ.

This is a myth. The processors are identical. The differences in labeling are related to marketing reasons.

brotherdg2@gmail.com wrote on 2025-04-05, 19:54:

This is a myth. The processors are identical. The differences in labeling are related to marketing reasons.

What is a myth? Do you mean that AMD 5x86 133ADW processor can survive higher temperature than 55 °C while working? I wouldn't risk to check this out with mu only 5x86 CPU (marked ADW).

brotherdg2@gmail.com wrote on 2025-04-05, 19:54:

This is a myth. The processors are identical. The differences in labeling are related to marketing reasons.

Yes and no, these were baked the same way but there are 3 different gens. ADW is the first, then can't ADY and finally ADZ. Due to slight enhancements in the procedure, the final were of a slightly better quality.
This results in a better chance of a good overclock at stock voltage and tolerance of higher temps.

Ofc this does not mean no ADW would ever run at 200MHz; it's a game of chance and luck with the odds being a little better with the ADZ

My BGC handles 4x40 and 3x50 at 3.3v perfectly fine. It can boot at 4x50 with 4V, but it doesn't get far.

analog_programmer wrote on 2025-04-05, 14:24:

4 V for AMD Am5x86-P75 X5-133ADW seems too much to me.

ADZ CPUs can work up to 85 °C, but ADW chips are limited to maximum of 55 °C. So ADW CPUs can withstand far less overvoltage and overclocking than ADZ.

At 160mhz I had no problems with both versions of the CPU. ( ADZ and ADW )