My friend's computer is running quite hot, and thus unbearably loud. I read the undervolting article and decided to try it myself.

I came upon a brick wall when it came to voltage changing. Default voltage for a duron (morgan) 1300 is 1.75v, and when i tried to change the voltage it only showed options of 1.75v up to 1.85v. I know for a FACT that the voltage can be set lower, since I can set the voltage from 1.5v to 1.85v for an Athlon XP 1800+ on the same Asus A7V8X-X motherboard.

How can I set to lower voltages under 1.75v with the duron? If necessary, what settings for the bridges on the cpu itself should i change?

Thanks

If you (he) doesn't change mobo, you must cut bridges on the CPU itself. ASUS-boards are very reliable, but have two shortcommings in a silent system. First of all, their stability comes from the fact that actual Vcore provided to the CPU is about 0.05V higher than set in bios. The second is that you can't undervolt an ASUS-board:(

To bad, realy, they are often realy good....

Yes, you can but it requires some hardware-mod. I reduced the
'bias' voltage on mine so the CPU overvoltage range now is the
normal range, and the normal is the undervolting range.

How did you do that?

yeah, how did you do that? does it require a lot of precise soldering or an extra circuit board?

I just unsoldered a pin at the voltage regulator that is
internally pulled-high. What pin depends on MB, CPU,
and the desired voltage reduction. In my case it was a L6917B
regulator from ST, on a A7V8X and a Palomino (at the time).

I don't remember exactly what pin I unsoldered (I can check
the next time I open my case), but I guess it was pin 19 or
20 depending on if I lowered it 0.1 or 0.2V. Basically you’re
overriding the CPU’s own VID-setting. But unlike cutting CPU
bridges, it’s a reversible operation.

You can mod any MB to almost any (reasonable) CPU Voltage,
but I wouldn't recommend it if your not feeling comfortable
using a solder iron in your computer. (the pitch or pin spacing
is usually 50 mil or 1.27mm). So check which regulator you’ve
got, download the datasheet and get starting!