General discussion

Only 8.9 to 9V on the 12V rail

I have an Asus P5KPL-AM EPU combined with HEC 500w raptor. It's brand new, and I noticed using EVEREST, the following readings:

+3.3 V : 3.41V
+5 V : 5.73 V
+12 V : 8.94 V (sometimes 9V)

My readings on my other computer with Asus P5Kpl-am/ps and also HEC 500w shows around 12.1 V on the +12V reading.

Don't you think there's undervoltage on the 12 V rail? Is there something wrong with my power supply or motherboard? The computer is stable, though.

Or is this the effect of Asus EPU engine? Have any of you experienced the same?

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Reply to: Only 8.9 to 9V on the 12V rail
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How did you measure this?

I use a Volt meter. That is, I read how you used Everest but given that that is prone to software errors did you confirm it with a real Volt meter?

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I didn't use a volt meter

No, I didn't use a volt meter, as it's really difficult to remove the power supply, and my lack of experience. I rely on EVEREST.

The question here is could possibly the Asus EPU engine causes this?

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I don't remove the power supply to use a Volt Meter.

That's quite odd to remove the power supply to measure the voltage. I know it's asking a lot but a Volt meter is the accepted method to measure voltages. Those motherboard and software methods are error prone.

As to your question the answer is yes. ALL these have been wrong from time to time. Don't trust them but use the real thing to measure with.

If you feel it should work, then it is a warranty item and something you won't be fixing.

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(NT) What's your BIOS show re voltages ?
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The BIOS shows 12.30V

It seems that the BIOS is showing correct voltages. The 12V rail shows 12.30 V. The cpu core is around 1.23V. Once the operating system Windows 7 is loaded the CPU core fluctuates from 1.08 to 1.20 depending on usage. The 12V shows 8.8 to 9 V.

Could this be the work of EPU engine? Do you have a motherboard with an EPU engine and shows the same?

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That''s possible ... can you disable it and rerun the system

info to see what it shows ?

Are you using the latest version of EPU ?


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The Asus EPU engine is hardware controlled

I can't disable the Asus EPU engine since it is hardware controlled

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If you really want to run the problem to ground, you

need to test the PSU with a voltmeter. If you're just curious about the variance and there's no actual problem like instant restarts or similar ... you might try posting the question in the ASUS Support forum for your product to see what other owners are experiencing.


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Looks like nothing is wrong here.

These software voltages are known to be off on some machines. Too many to even check if yours is one of them.

All of us know not to trust them.

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