BIOS and HWMonitor 12V rail readings do not agree

TheRealMrGrey

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Jan 20, 2007
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I was looking at HWMontior and it claims my +12V rail is 2.11 V. It also claims my +5 VCCH is 3.58V.

However, I went into my BIOS and the BIOS claims my +12V rail is 12.4V.

My question is whether they both can be right - and if not, what should I trust? I know, I can go buy a multimeter and measure it - I don't own one but will pick one up.

In the mean time, can the +12V rail read 12V when in BIOS without the OS loaded, but then go down when the OS is loaded due to power draw by components?

Usually one would physically measure the rail with the system off for safety? But if the voltage drops under load, measuring the voltage with the system off will tell me nothing.

I have had some stability issues lately, but I don't know what component is causing it (I determined it was likely the MB based on the research I did, and decided to back off the BCLK a bit which did increase stability).

Note that CPUID PCWizard gives the same low voltage readings as HWMonitor.
 

TheRealMrGrey

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Jan 20, 2007
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I forgot - the Antec Earthwatts EA650 has three +12V rails...

http://pdfs.icecat.biz/pdf/21834846-2488.pdf

http://www.newegg.com/Product/Produc...82E16817371015

So is it possible that one of the rails has gone bad and HWMonitor is measuring one, while the BIOS is measuring another?

How would I go about measuring the proper voltage with a multimeter on a 3-rail system? It isn't as if the PSU has 3 separate, obviously labeled rails. It has the usual outputs for a desktop setup - MB power, CPU power, 2 GPU 6-pin powers, SATA powers, 4-pin fan powers, etc.
 

TheRealMrGrey

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Jan 20, 2007
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On further review of the literature, it is suggested that the BIOS reading should be taken over software monitors. I find the HWMonitor numbers difficult to believe, I would expect the computer would not post at 2.11V.