Voltage problem?

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Voltage problem?

Postposted on Thu Mar 12, 2009 1:07 am

Using CPUID's Hardware Monitor, I'm apparently getting 10.05V on the +12V, -8.64V on the -12V and -8.64V on the -5V. Everything else is normal. I appear to be woefully undervolted on the 12V and overvolted on the 5V, but I haven't had any stability issues. Should I be concerned about these readings? If I should be having problems, how would they manifest?

Thanks.
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 1:21 am

If that +12V reading is accurate, yes you have a problem. However, given that the system seems stable, it is more likely that the reading is simply incorrect.

Many newer PSUs omit the -5V rail entirely, as modern motherboards no longer use it. The reading is probably meaningless.

Given that the reading for your -12V rail is identical to the (most likely bogus) reading for the -5V rail, I suspect that CPUID simply doesn't know how to read the -12V on your motherboard, or the motherboard does not have a sensor for it.

Does your BIOS have page that displays your voltages? If so, what does it say?
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 2:51 am

D'oh, why didn't I think to check my BIOS readings. Good call jbi. BIOS reports 11.840V on the 12V and 4.99V on the 5V. The -12V and -5V don't show up on there, but at least the 11.84 is a lot better than 10.05 on the 12V.
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 4:27 am

10 V seems rather shaky anyway, that kind of voltage would have serious trouble spinning up your hard drives or even opening your optical disc tray.
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 7:44 am

Usually a 5% tolerance is completely fine, and a 10% on the 12V line is normally acceptable. At least that's the rule of thumb I've always used.
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 7:48 am

If you are concerned about the voltages on load, you can see if the motherboard CD comes with a monitoring tool for use.
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Re: Voltage problem?

Postposted on Thu Mar 12, 2009 9:48 am

I always worry more about stability than voltage readings. If it's stable you're probably not going to hurt anything. Power circuitry has become robust enough that it either works or it doesn't, without middle ground. You'd notice if you had a problem where your system was at risk.

Alternatively, you can take a volt meter to the +12 (yellow) and +5 (red) and +3.3 (orange). Still, take these measurements with a grain of sand, though. There can be wild voltage drops in use, 18 amps is a lot of current.
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Re: Voltage problem?

Postposted on Sun Mar 22, 2009 1:56 pm

uh...mines too. i used Everest Ultimate 4.60.1500 to run system stabilities test, i noticed that the +12V is between 8.76 - 8.87V
firstly, i thought that's my PSU is in trouble, but when checked in the BIOS is just 11.89V. Whatever , my system is run stably

i will try another soft to check it again
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Re: Voltage problem?

Postposted on Sun Mar 22, 2009 7:22 pm

honoradept wrote:uh...mines too. i used Everest Ultimate 4.60.1500 to run system stabilities test, i noticed that the +12V is between 8.76 - 8.87V
firstly, i thought that's my PSU is in trouble, but when checked in the BIOS is just 11.89V. Whatever , my system is run stably

i will try another soft to check it again

If that were true your computer would not be on. Not even close.
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Re: Voltage problem?

Postposted on Mon Mar 23, 2009 4:01 am

SpotTheCat wrote:
honoradept wrote:uh...mines too. i used Everest Ultimate 4.60.1500 to run system stabilities test, i noticed that the +12V is between 8.76 - 8.87V
firstly, i thought that's my PSU is in trouble, but when checked in the BIOS is just 11.89V. Whatever , my system is run stably

i will try another soft to check it again

If that were true your computer would not be on. Not even close.



Here is my test

Image

Any suggestion would be appreciated....
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Re: Voltage problem?

Postposted on Mon Mar 23, 2009 5:43 am

honoradept wrote:
SpotTheCat wrote:
honoradept wrote:uh...mines too. i used Everest Ultimate 4.60.1500 to run system stabilities test, i noticed that the +12V is between 8.76 - 8.87V
firstly, i thought that's my PSU is in trouble, but when checked in the BIOS is just 11.89V. Whatever , my system is run stably

i will try another soft to check it again

If that were true your computer would not be on. Not even close.


Here is my test...Any suggestion would be appreciated....


I think what Spot meant by his post was that it is the software lying to you and us. Not that you were lying to us. Don't get uppity.

If the BIOS says that your voltage on the +12V line is +11.89V, then you have nothing to worry about. I believe a 10% variance is well within acceptable limits. Like Spot said, if you were really that far off from +12V, your system wouldn't be able to run.

There doesn't seem to be a standard method of reporting voltage and system temps. So, I really only look at what the BIOS has to say. If there is software provided by the motherboard manufacturer for my specific model of motherboard, then I'll use that to see what's going on. But, my system is stable, so I just leave well enough alone and I don't bother looking.
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