I mean the topic is Worlds Fastest 486, and the Intel DX4-100 in 3V isn't rare... try running it in 3x mode and raising the voltage slightly until it works. The raised voltage might make the VLB card at 40Mhz more stable.

Each voltage increase raises the temperature and potential damage due to high temperature. Overly cooling it (cool to the touch) should prevent damage.

If you don't quite get enough speed/stability, try another CPU.

Motherboards with VLB often have a "=>33 MHz" jumper that needs to be changed.

SRAM should be 20ns or faster.

Performance should be significant... but also changing video cards gives significant results.

MikeSG wrote on 2024-11-12, 16:08:

I mean the topic is Worlds Fastest 486, and the Intel DX4-100 in 3V isn't rare...

I know, that why i said that was a random question.. I Just wanted to know what should be faster.. A intel dx4-100 3.3v with vlb fsb33, or amd dx2-80 3v with vlb fsb40..

Oh I thought you wanted to overclock the DX4-100 to run on a 40Mhz FSB.

MikeSG wrote on 2024-11-12, 16:08:

Motherboards with VLB often have a "=>33 MHz" jumper that needs to be changed.

SRAM should be 20ns or faster.

Many VLB cards just ignore this jumper.

For real fast 486's the SRAM speed should be 12ns or non-faked 10ns.
You likely will need an oscilloscope to measure the exact SRAM timing. "ISSI 10ns" 128K x8 SRAMs will be most likely 15ns chips.

pitchshifter wrote on 2024-11-13, 18:54:

MikeSG wrote on 2024-11-12, 16:08:

I mean the topic is Worlds Fastest 486, and the Intel DX4-100 in 3V isn't rare...

I know, that why i said that was a random question.. I Just wanted to know what should be faster.. A intel dx4-100 3.3v with vlb fsb33, or amd dx2-80 3v with vlb fsb40..

Still i didnt understand witch conbination should be the Best 😅

pitchshifter wrote on 2024-11-15, 10:49:

Still i didnt understand witch conbination should be the Best 😅

Not sure this thread is the best spot for these questions, but its going to partly depend on what application/game is most important to you. If the bottleneck is the CPU - DX4-100 is going to beat DX2-80. If the bottle neck is videocard bandwidth - then its possible a DX2-80 with 40mhz VLB might be better in specific cases. IMO the DX4-100 with 33mhz VLB would be the best all round choice.

Also a bit motherboard side silicon lottery dependant, if your chipset, cache and RAM can run 40Mhz at with the same wait states and timing as 33Mhz, it's faster, if you have to add waitstates it might be a wash. Which is something ppl frequently find between 33 and 40mhz.

Disruptor wrote on 2024-11-14, 10:49:

Many VLB cards just ignore this jumper. […]
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MikeSG wrote on 2024-11-12, 16:08:

Motherboards with VLB often have a "=>33 MHz" jumper that needs to be changed.

SRAM should be 20ns or faster.

Many VLB cards just ignore this jumper.

For real fast 486's the SRAM speed should be 12ns or non-faked 10ns.
You likely will need an oscilloscope to measure the exact SRAM timing. "ISSI 10ns" 128K x8 SRAMs will be most likely 15ns chips.

Indeed, I own some of those fake 10ns in 128k x 8 and 64k x 8, the logos are obviously different and even running where 15ns should be ok they just barely pass. Searching high and low I could only find confirmation of 32k x 8 being being made in 12 and possibly 10ns (I own 12s and they seem legit) by ISSI, pretty sure anything marked 10ns in higher capacity is fake. You are better off sourcing genuine ISSI 15s and cherry picking the better ones if need be