Athlon XP-M Voltage



New Member
Originally I had a Barton 2.2Ghz CPU (3200+) rated 1.65cc

I didn't like how warm it got (pushes 60c durring heavy load) so found a XP-M 2133Mhz. Rated for 1.55vcc

Had to pin-mod to force 200/400 fsb since everything is unlocked and bios defaulted to minimum fsb and multi. Using RMCLOCK to modify Multiplier in windows.

This all works fine.

But, I'm getting 1.65 vcc and don't know if I can change it somehow.

My goal is to incrementally lower voltage so I can keep my speed 2.2Ghz but run at lowest voltage.

Currently I can go as High as 2.3 Ghz perfectly stable (and 2.5 as long as I don't stress it) but I really just want lower temps/power consumption so 2.2 max is all I really care about.

I don't exactly know how voltage is provided.
Motherboard does not respond to VID.

L11 bridges on CPU seem to be calling for 1.55vcc
I tried pin-moding down but the board acts as if 1.65 is already jumpered in place.

See here:

Look at the 1.650 vcore and the 1.675 vcore settings.
I tried 1.675 to see how high I could go stable at first but the actual result was 1.850

When you look at the 1.850 pin mod you can see that it is the sum of the 1.650 and 1.675 jumpers...but I only had the 1.6750 in place.
Is the motherboard "pre-jumpered" ?

using KM400 based motherboard.
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Procrastinating Member
Your other thread mentioned this board was out of an HP. I suspect this is why it's locked, and I would speculate that it would be done in the bios, since it's easier than doing a hardware mod. Years ago with the old style rectangular bios chips I hot-flashed an HP board to the board manufacturer's bios. Doubt I'd dare trying that again these days.


New Member
I see. Thanks for the insight.

I guess I would have to understand more about how voltage is applied or selected...There HAS to be a way...I know in the old days if you couldn't get the voltage you wanted, you could just add or change a resistor on the mobo and therefore manipulate what voltage was actually sent to the cpu. Is there commonly a voltage selector circuit on motherboards??

I've also been looking for what pins voltage and ground are applied...I mean if it comes to that, there should be some way I could supply about 1.6v with enough current to support the cpu. Found some pdf data sheets but cannot view them from this location..arg. Will just have to wait.
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