My PSU is going below 12v

tweakboy

Diamond Member
Jan 3, 2010
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Ok my voltage in HWmonitor is 11.99v on the 12v rails

When I OC this goes even lower, and my OC crashes.

Im scared to play any games right now ..... cuz PSU voltage dips below 12.

things used to be fine @ 12.096 in winblows and 12.1xx in BIOS on the OC

2.4Ghz :eek::thumbsdown:

I dont want the PSU to kill the Mobo again.... sighs D:
 

jimmybgood9

Member
Sep 6, 2012
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11.99 is great. How low does it go when you OC? I believe the official tolerance is +-5%, so as low as 11.4 should be acceptable. Now that's too low for me, but IMHO 11.8, for example, is perfectly acceptable. What do +5 and +3.3 look like?

But, really, the big concern with PSs is the fluctuations, the ripple and noise that you can only see on a scope. So, I would recommend a high quality PS, whether you're OCing or not. Even if the system is stable now with acceptable nominal voltages, a cheap PS can fry all you expensive parts. Of course, any OCed part could be the problem.
 

Blain

Lifer
Oct 9, 1999
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You need to run some extensive benchmarks on the PS.
That will give you a better picture of the quality than a single voltage reading.
 

tweakboy

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Im scared to. Same thing will happen and PSU will kill mobo. Gosh 2.4Ghz blows plus I cant play games right now at least... darn PSUs are always soo expensive the good ones...
 

bryanl

Golden Member
Oct 15, 2006
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11.99V is 60 times better than the ±5% tolerance allowed by ATX standards, but there's no way to be certain of the voltage without measuring it with a digital multimeter since readings taken by software, even the BIOS, are not particularly accurate.
 

Rvenger

Elite Member <br> Super Moderator <br> Video Cards
Apr 6, 2004
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Your CPU has degraded or you have a bum motherboard. Probably why it was for sale used.

Try updating the Bios.
 

Blain

Lifer
Oct 9, 1999
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Im scared to. Same thing will happen and PSU will kill mobo. Gosh 2.4Ghz blows plus I cant play games right now at least... darn PSUs are always soo expensive the good ones...
A good quality PS is the backbone of a system.
Don't leave home without one.
 

tweakboy

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Jan 3, 2010
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Your CPU has degraded or you have a bum motherboard. Probably why it was for sale used.

Try updating the Bios.

Guys for 5 years my mobo showed 12.1xx in BIOS and 12.096 in windows and I could OC to 3.7Ghz Now in the BIOS it shows 12.040 and in windows it shows 12.040 Soo its the PSU giving me this OC issue.


Your right man. Also the BIOS was already upgraded to 1201 2008 latest.

The guy had it OCed to 3Ghz when I checked the BIOS 333Mhz ..... :thumbsdown:


Gosh 2.4Ghz and no gaming.. dat sux! I think its upgrade time soon. Im gonna jump on Haswell 6 core and never look back for 10 years. lol
unless Sandy E is 6 core. :)
 
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tweakboy

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Awww man I knew I shouldn't have bought used.... it was still 45 to the door, new one we couldnt find I think we found one for 100 dollars or soo.

OR the mobo is bunk and doesnt allow nice proper voltage of 12.1xx and 12.096 after OC
now its stuck at 12.040v in BIOS and same in windows.. If I OC the voltages go down a bit and I think that is what killed my mobo, I cant risk it right now I cant game... I dont want same thing to happen.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,369
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Tweak, my friend. I have a DFI X48 board, BNIB, in my FS thread.

Its twin OCed a Q6600 to 3.6 nice and easy.

But if you buy it, don't burn it up with a shitty PSU, please. It was a $260 mobo when I got it.
 

bryanl

Golden Member
Oct 15, 2006
1,157
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Guys for 5 years my mobo showed 12.1xx in BIOS and 12.096 in windows and I could OC to 3.7Ghz Now in the BIOS it shows 12.040 and in windows it shows 12.040 Soo its the PSU giving me this OC issue.
That would likely be true if the CPU operated directly from the 12V, but the input volage goes through an onboard regulator that tolerates rather wide variations, down to 10-11V. But just as capacitors can fail in power supplies, they can also fail in onboard regulators and prevent the CPU from receiving sufficient voltage.

It's possible the perfectly fine 11.99V reading is wrong and your PSU is actually out of tolerance, but the only way to be certain is with a multimeter.
 

tweakboy

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Jan 3, 2010
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Thanks byranl and all gurus.

Im thinking the mobo wont give a voltage above 12.040 .. this is the used mobo I got but I dont think its the mobo. With my otherboard I got 12.1 in bios and 12.096 in windows after OC. Now I cant OC whatever I try doesnt work.

2.4Ghz :thumbsdown::thumbsdown::thumbsdown:
 

Quiksilver

Diamond Member
Jul 3, 2005
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This, geez. It took me this long to find this in the thread?

Guys, he's reading the damned voltages from software and BIOS which is known to be inaccurate.

On top of that, even if they happened to be right for once, he is still within ATX specifications.

Right now as is, if his OC is failing, it is quite possible he just needs to increase the voltage to his RAM or CPU. For all we know his RAM is starting to crap out on him.

:whiste:
 

Blain

Lifer
Oct 9, 1999
23,643
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Don't worry, tweakboy will conduct extensive testing with highly accurate measurement instruments.
We are awaiting those results.
 

bryanl

Golden Member
Oct 15, 2006
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Im thinking the mobo wont give a voltage above 12.040 .. this is the used mobo I got but I dont think its the mobo. With my otherboard I got 12.1 in bios and 12.096 in windows after OC.
Those readings can't be compared, unless they were verified with a multimeter, since motherboard hardware does not measure voltage with high accuracy. You're dealing with differences of just .5%, and even many multimeters aren't that accurate.

You need to read the voltage reaching the CPU and see how it varies with load, and this can be done with the motherboard hardware since it involves looking only at voltage changes, as opposed to absolute voltages. It's possible the motherboard's capacitors have gone bad.
 

tweakboy

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Jan 3, 2010
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That would likely be true if the CPU operated directly from the 12V, but the input volage goes through an onboard regulator that tolerates rather wide variations, down to 10-11V. But just as capacitors can fail in power supplies, they can also fail in onboard regulators and prevent the CPU from receiving sufficient voltage.

It's possible the perfectly fine 11.99V reading is wrong and your PSU is actually out of tolerance, but the only way to be certain is with a multimeter.


Thank you cute dog. You are right good info.