Is this a normal 12V motherboard voltage?

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Matrox462

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Feb 25, 2004
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I just installed a Gigabyte K8NSC-939, and so far this board works great with no problems what so ever. The only thing I noticed was that EasyTune was reporting the 12V as 11.470V-11.350V. Is this within range? Could it just be flakey reporting? I have a 400W PSU that has built in voltage readouts for 3.3V and 5.0V and both are rock solid at their proper voltages. This is the same power supply that I've been almost using for a year with a 6800GT so I'm postive this is a stable PSU.

The other voltages EasyTune reports are:
VCoreA at 1.400-1.420V
+3.3V at 3.280V
 
im not 100% sure, only 99%, but i believe what is going on here the fact that electricity needs electiricity to move electricity :D. basically, as the elecricity moves throughout the wiring, some of it is lost due to resistance. there is NO way to get all 12V to the mobo. as of now your doing great
 
That's a little low for a 12V rail. You definitely be above 11.50V or more (mine is at 11.90V). You might have some stability issues with a 12V rail that low.
 
They are supposed to be within 5%, that means as low as 11.4V and as high as 12.6V but any more or less is out of spec.

==>Lazn
 
So basically, you're flirting on the edges of where you need to be ;).
 
Thanks for the responses guys. As I suspected, I thought there'd be like a +/-5% voltage tolerance. I doubt it's the rail that's not supplying the full 12V, it could be that like Panda Man said, it's losing 500mV due to resistance.

I guess I could always stress test it to see how stable it is. :p

BTW, this maybe a stupid question, but do you think there'd be any way to up the voltage via the BIOS? I know for a fact I can control RAM, CPU, and AGP voltages.
 
Matrox462 said:
BTW, this maybe a stupid question, but do you think there'd be any way to up the voltage via the BIOS? I know for a fact I can control RAM, CPU, and AGP voltages.
Click to expand...

Nope, as this is the source for those votlages, in the BIOS you can control the VRM's that are on the motherboard, but not the source in the powersupply that is not on the motherboard.

==>Lazn
 
Pandaman's explaination doesn't quite add up. Yes if you have 12V at the powersupply you will have 12V at the motherboard, Voltage is not a measurement of electricy it is more of a measurement of potential difference. If you have 12V of difference between the wires at the powersupply output you will have the same 12V of difference at the input to the motherboard.
(edit: there is such a thing referred to as DC wander, but then your talking great distances.)

I never liked trusting the onboard voltage monitors. If you had access to an accurate DMM, I would definitely be good to verify it but not totally necessary.

Your probably just fine, as long as your system boots up and is stable I wouldn't worry about it.
 
Menelmarar said:
Pandaman's explaination doesn't quite add up. Yes if you have 12V at the powersupply you will have 12V at the motherboard, Voltage is not a measurement of electricy it is more of a measurement of potential difference. If you have 12V of difference between the wires at the powersupply output you will have the same 12V of difference at the input to the motherboard.
(edit: there is such a thing referred to as DC wander, but then your talking great distances.)

I never liked trusting the onboard voltage monitors. If you had access to an accurate DMM, I would definitely be good to verify it but not totally necessary.

Your probably just fine, as long as your system boots up and is stable I wouldn't worry about it.
Click to expand...

I just checked with a multimeter, and the 12V readout on the meter was not the same readout as on EasyTuner. EasyTuner was about 50-100mV less than the actual read out. I was getting a reading of about 11.50V on the meter, and the lowest it ever went while being stressed was 11.48V. That is within the 5%. Also, I noticed in the BIOS there's a board health section and it says "12V OK". So even the BIOS says the voltage is fine.

Guess I should be fine then! Thanks everyone!
 
Matrox462 said:
I just checked with a multimeter, and the 12V readout on the meter was not the same readout as on EasyTuner. EasyTuner was about 50-100mV less than the actual read out. I was getting a reading of about 11.50V on the meter, and the lowest it ever went while being stressed was 11.48V. That is within the 5%. Also, I noticed in the BIOS there's a board health section and it says "12V OK". So even the BIOS says the voltage is fine.

Guess I should be fine then! Thanks everyone!
Click to expand...

That's still pretty close to the point where I'd think you'd start losing stability. It might depend on what you have running of the 12V rail.
 
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