A little down and to the left it says:

1VIO     JP12
23.31V   1-2
33.48V   2-3

It's literally in your pic, just hard to read (I happen to have an AX59 Pro in front of me so I checked). 🤣

Can't believe I missed that. Thanks! Even after you pointed it out it took me a minute to spot it. Better get my eyes checked.

How do you have your board configured? I don't know anything about the "vio" setting.

VIO is I/O Voltage. Most Socket 7 CPUs have 3.3V as the recommended value, with 3.46-3.6V as the max (according to CPU-World, at least). So it's at 1-2 and I left it there.

For example:
http://www.cpu-world.com/sspec/SL/SL27J.html
http://www.cpu-world.com/CPUs/K6-2/AMD-K6-2%2 … 6-2-475AHX.html

My AX59 Pro only runs stable with 112MHz FSB, if I set the I/O Voltage to 3.48V. With 3.31V, I get heavy errors, like data corruptions. It has nothing to do with the 1MB On Board L2 Cache, because also after disabling, the same errors appears with 3.31V I/O Voltage.