I run a K6-3 on an Asus TX97-XE. All you need before the software tweaks are a compatible voltage supply and perhaps a BIOS update.

flupke11 wrote on 2022-04-27, 07:23:

I run a K6-3 on an Asus TX97-XE. All you need before the software tweaks are a compatible voltage supply and perhaps a BIOS update.

Interesting. What CPU does it detect in the POST screen? Did you use the K6-Pro tool or something else? The K6-2 needs 2.2V, my board goes only down to 2.8V but I think this should be okay.

Edit: But the CPU needs 3.3V I/O voltage, my board only supports 3.52V, could this be a problem?
Edit2: Wrong, it has normal 3.3V I/O. I probably got confused by the manual, the 3.52V is about VRE and has nothing to do with I/O voltage.

It correctly detects the K6-3, I did not use the software tool yet, it was more of a proof-of-concept.

Although your board accepts split voltage CPU's, I'm not sure about it supporting k6-2, as it's a fairly old chipset. I haven't looked into it any further, though.

I/o voltage mostly doesn’t matter

My PCCHIPS m590 outputs 3.9 volt I/o when set for 90mhz FSB

That's good to know, I have never overvolted the I/O, thought it might be sensitive. Anyway, if anyone else has tried this, please share your experiences. There is surprisingly little info about this subject. If there are no objections, I will definitely try this in the following weeks.

Upping the I/O voltage can help when overclocking the chipset / fsb.

I would make sure you have better than normal cooling for the CPU when running it at a higher voltage.

The K6-2 chips can get very very hot when overvolted. Back in the day, when I was running my K6-2 550 at 660Mhz, the heatsink got blazing hot even with a high power fan pointed at the heatsink in addition to the fan on the heatsink.

Newer / infinitely better PSUs and also newer coolers (thin fin and heatpipe) help a lot in that regard.

I finally tried it, it works!

Inspired by this thread: Running a K6-2 at single voltage? - running a K6-2 at 3.3V on an unsupported single voltage board.

I set the board to 2.8V, the lowest possible voltage, intended for Pentium MMX processors. This is how the board identified the CPU:

The actual clock speed is 66 x 2.5 = 166 MHz, but the BIOS would always detect it as 66 MHz. The CPU heatsink didn't get very warm. But the voltage regulator runs very hot at 2.8V, I almost burned my finger, so I did not dare to run the CPU at the default speed of 400 MHz. Newer Socket 7 boards usually have multiple voltage regulators to split the load and keep the temperature reasonable.