Are you sure it's not just the CPU? What happens if you drop the multiplier to 3x and try it at 120MHz (3x40MHz)?

I have three Am5x86 CPUs that happily do 3x50MHz but don't manage it at 160MHz, even if I raise voltage to 4V.

Am5x86 CPUs do regularly reach 160MHz and some even do 200MHz, but that doesn't guarantee they all do...

Here is a image from “Speedsys” program of what your benchmark score should look like for the GA5486AL over clocked with an AMD 5x86-133-P75 @ 160mhz.

most of my 5x86 amd. overclock to 160 always, but 1 chip does it 50% of the time. Once I was using that chip and I was sure the motherboard is faulty until I realised it works fine with other 5x86 chips at 160 just not one.

Also for more performance have you adjusted your memory timings in bios?

Memory timings is a good place to start. Not every stick can deal with 40 MHz at the fastest settings and even many cache chips can't take it. But with relaxed timings you should be safe.

Most VGAs I've ever tried could deal with 40MHz PCI. A Virge should be ok with it.

CPUs, on the othet hand... Of 20+ 5x86s there were a few that didn't even POST or boot DOS at 160 MHz stock voltage and only a few (I kept like 3 or 4) are stable in every motherboard, 3.3 or 3.45 Volts. Let alone my Shuttle HOT-433 with bulging caps which can overclock only ONE of those. Time to repair, I guess.

Does it work with L2 cache disabled and memory timings set slow? Single-banked cache implementations, such as that used on this board, will not handle fast timings at 40 MHz. Also, try a simple graphics card, like a Virge.

Some of the 5x86s don't overclock well. I have about five of these chips, and most do overclock pretty easily, but I have an ADZ which refuses to do 160MHz stably at any voltage, which is funny because ADZ was always regarded as superior to the ADW. I have 3 or 4 ADW chips and all overclock to 160, but my lone ADZ is a real turd.

Well i'll be damned!

Thanks for the help guys, great success!

I ended up just switching it to 40mhz with the 4x multiplier. Then disabled L2 cache, turned the memory timings to the slowest and then BEEP! it booted..... Happy times. I had done this prior, but never turned off the L2.

Then i turned on the L2..... BEEP! my jaw dropped.....

so, i thought let's just go all in.... Turned all my timings to 2-1-1-1 and set them to fastest.....
BEEP! what the hell???

Anyway, stock voltage 160Mhz and boots to windows without skipping a beat..... Here's my speedsys results.

This is why playing with old pc's is fun.... Because it seems you just need to choose the right day and hold your tongue the right way to get results!

I think I am using setting of:

Bios settings:
Clk/5
Timing = 3-1-1-1
WS=0

maybe someone will find it interesting
https://streamable.com/cu5k43

Does anyone know how to get the bus to 60MHz on this GA-5486AL motherboard?

According to this video it's possible but the documentation only provides details for 25, 33 and 40MHz.

https://www.youtube.com/watch?v=Zg8S0pUEHAQ

byte_76 wrote on 2025-04-21, 06:23:

Does anyone know how to get the bus to 60MHz on this GA-5486AL motherboard?

According to this video it's possible but the documentation only provides details for 25, 33 and 40MHz.

https://www.youtube.com/watch?v=Zg8S0pUEHAQ

that is my video, here you go

Hmmm... That's different than what I have in my notes, which was:

I might need to double check this.

Did you confirm your settings with an oscilloscope? Does this motherboard work well at 180 MHz with an Am5x86?

feipoa wrote on 2025-04-24, 13:34:

Hmmm... That's different than what I have in my notes, which was: […]
Show full quote

Hmmm... That's different than what I have in my notes, which was:

The attachment GA-5486AL_60-60_MHz_FSB.jpg is no longer available

I might need to double check this.

Did you confirm your settings with an oscilloscope? Does this motherboard work well at 180 MHz with an Am5x86?

The motherboard is completely stable — I’m still using it with those settings. The CPU doesn’t even need to run at 4 volts; 3.3V is enough. It just stayed at 4V because I originally tested it at 4x50MHz. But at 3x60MHz, it runs perfectly stable without a single error. If you’d like to see, I have two older videos I recorded back then, and I also made a new one where I upgraded it with a Voodoo 3 PCI — though I haven’t uploaded that one to YouTube yet.

https://youtu.be/r7CgqW-mj8Y
https://youtu.be/Zg8S0pUEHAQ

Thank you very much. Looking forward to trying this with my board and CPU.

My CPI doesn’t reach 160 at 3.3V but it works on 4V.

ReL wrote on 2025-04-24, 13:28:

that is my video, here you go […]
Show full quote

byte_76 wrote on 2025-04-21, 06:23:

Does anyone know how to get the bus to 60MHz on this GA-5486AL motherboard?

According to this video it's possible but the documentation only provides details for 25, 33 and 40MHz.

https://www.youtube.com/watch?v=Zg8S0pUEHAQ

that is my video, here you go

I've tested those jumper settings but my board doesn't post. It beeps with fast short beeps that sounds like stuck keys on the keyboard.
Same result with the video card removed. (S3 Virge DX)

My processor is an Am5x86 P75 ADW and I have the voltage set at 4V with the rest of the jumpers configured for an Am486 DX4-100 Enhanced.

Can you please share the other jumper config around the CPU and your BIOS settings, particularly the memory and CLK settings under Integrated Peripherals.

Maybe it’s the memory that is having issues with this speed but I've tested all my modules and none boot.

byte_76 wrote on 2025-04-24, 16:17:

I've tested those jumper settings but my board doesn't post. It beeps with fast short beeps that sounds like stuck keys on the k […]
Show full quote

ReL wrote on 2025-04-24, 13:28:

that is my video, here you go […]
Show full quote

byte_76 wrote on 2025-04-21, 06:23:

Does anyone know how to get the bus to 60MHz on this GA-5486AL motherboard?

According to this video it's possible but the documentation only provides details for 25, 33 and 40MHz.

https://www.youtube.com/watch?v=Zg8S0pUEHAQ

that is my video, here you go

I've tested those jumper settings but my board doesn't post. It beeps with fast short beeps that sounds like stuck keys on the keyboard.
Same result with the video card removed. (S3 Virge DX)

My processor is an Am5x86 P75 ADW and I have the voltage set at 4V with the rest of the jumpers configured for an Am486 DX4-100 Enhanced.

Can you please share the other jumper config around the CPU and your BIOS settings, particularly the memory and CLK settings under Integrated Peripherals.

Maybe it’s the memory that is having issues with this speed but I've tested all my modules and none boot.

I have around 40 AM5x86 processors, and only 2 of them run stably at 180MHz and 200MHz. So it's likely more about the CPUs themselves than the jumpers. As soon as a processor requires more than 4V just to run at 160MHz, it means further overclocking is neither possible nor stable.

byte_76 wrote on 2025-04-24, 16:17:

I've tested those jumper settings but my board doesn't post. It beeps with fast short beeps that sounds like stuck keys on the k […]
Show full quote

ReL wrote on 2025-04-24, 13:28:

that is my video, here you go […]
Show full quote

byte_76 wrote on 2025-04-21, 06:23:

Does anyone know how to get the bus to 60MHz on this GA-5486AL motherboard?

According to this video it's possible but the documentation only provides details for 25, 33 and 40MHz.

https://www.youtube.com/watch?v=Zg8S0pUEHAQ

that is my video, here you go

I've tested those jumper settings but my board doesn't post. It beeps with fast short beeps that sounds like stuck keys on the keyboard.
Same result with the video card removed. (S3 Virge DX)

My processor is an Am5x86 P75 ADW and I have the voltage set at 4V with the rest of the jumpers configured for an Am486 DX4-100 Enhanced.

Can you please share the other jumper config around the CPU and your BIOS settings, particularly the memory and CLK settings under Integrated Peripherals.

Maybe it’s the memory that is having issues with this speed but I've tested all my modules and none boot.

Most Am5x86 CPUs cannot handle 180 MHz at any voltage. If you need to run your Am5x86 at 4V for only 160 MHz, you will never get 180/200 MHz working. Best bet for 180 MHz at 3.3 V is a QFP Am5x86 from 2003. For 200 MHz to be long-term stable, you will need some active cooling, like a peltier cooler, but then you have problem with moisture.

ReL wrote on 2025-04-25, 08:39:

I have around 40 AM5x86 processors, and only 2 of them run stably at 180MHz and 200MHz. So it's likely more about the CPUs themselves than the jumpers. As soon as a processor requires more than 4V just to run at 160MHz, it means further overclocking is neither possible nor stable.

At what voltage are your Am5x86 chips stable at 200 MHz and in which motherboards? Are you using only a heatsink/fan inside a computer case, are did you add some active cooling? What stability testing did you perform at 200 MHz with the CPU inside a computer case? Thanks!

feipoa wrote on 2025-04-25, 08:44:

ReL wrote on 2025-04-25, 08:39:

I have around 40 AM5x86 processors, and only 2 of them run stably at 180MHz and 200MHz. So it's likely more about the CPUs themselves than the jumpers. As soon as a processor requires more than 4V just to run at 160MHz, it means further overclocking is neither possible nor stable.

At what voltage are your Am5x86 chips stable at 200 MHz and in which motherboards? Are you using only a heatsink/fan inside a computer case, are did you add some active cooling? What stability testing did you perform at 200 MHz with the CPU inside a computer case? Thanks!

I've managed to push my Am5x86 chip to 200 MHz on several different motherboards using the same CPU. I don’t have a complete list of the boards right now, but I can take some photos and share them when I get the chance. Even the GA-5486AL board can run at 4×50 MHz with some minor modifications.

As for voltage, I'm running it at 4.0V. For cooling, I'm using a Socket 7 heatsink with a fan spinning at around 5000 RPM. Regarding stability testing — I started working on that, but something came up and I had to put the project aside for a while. Still, I'm thinking about revisiting it and continuing where I left off.