12V PSU rail lower limit

PhireSide

PhireSide

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Allo guys

Just a quick Q - what is the minimum voltage a power supply should put out on its 12V rail? I understand they do fluctuate a bit, but I just want to know what the minimum safe limit would be
 
Not really a dipping one, but HWmonitor kept on reporting 10.7 - 10.8V on the 12V rail. Tested it with a multimeter and as true as Bob, 10.75V stable. Gonna try another PSU tomorrow and see if it helps
 
wabbit16 said:
Not really a dipping one, but HWmonitor kept on reporting 10.7 - 10.8V on the 12V rail. Tested it with a multimeter and as true as Bob, 10.75V stable. Gonna try another PSU tomorrow and see if it helps
Click to expand...
Stable you say, with or without load, maybe the supply have a 12V adjustment or are just loaded to much. If the latter try a higher wattage supply
 
What is your PC specs and what model PSU do you have?

Your 10.7V reading is quite a bit out of the ATX specs of 5% tolerance.

HWMonitor reports the following for my Corsair AX850 + i7 940 + 2x GTX 460:
+3.3V = 3.28 - 3.30V
+5V = 4.87 - 4.90V
+12V = 11.60 - 11.65V

Update:
The high voltage values are during idle and the lower ones are during load.
 
Last edited:
I had the m/meter showing the readout at idle and while I was playing Dirt 2. It didn't fluctuate at all.

A while ago I had a thread about my PC's issue - whilst in a game, the screen would turn off, my GTX570 would spin its fan 100% and I would have to hold the power button on for 4 seconds to turn it off. I would then have to unplug it from AC power and plug it back in to get it to turn on. If I did not unplug, it would give the no-vga beep sequence.

I first thought it was my motherboard, but that was replaced with a new unit.

My system is about 2 months old, FWIW.

Asus P8P67-M Pro (B3 rev.)
Intel Core i5 2500K
EVGA GTX570 HD
2*2GB XMS3 DDR3-1333
4 SATA HDD's
Corsair HX650 PSU
 
Your PSU should be more than capable of running that kind of PC.

I'd guess that the PSU is to blame, or perhaps your input voltage into your PSU isn't 230V @ 50Hz.
 
Funnily enough the other outputs are fine...they are as follows:

VCore - 0.904V (at idle)
+5V - 5.040V
+3.3V - 3.376V

I booted up my old PC with a new ThermalTake LitePower 430W psu in, and there I could get a 12.15V output on the +12V rail. So I think my Corsair is really not well, but I'll test it with another PSU if I get a chance.

My friend tested the GPU in his PC, and it worked fine, so I am ruling out motherboard and GPU this time. Also, my Windows install is about 2 weeks old, and I have no other software installed, so I don't think it's software related. Arg...issues issues issues :(
 
your m/meter also has a tolerance, and on the cheapie models it can be quite a bit.
 
I agree that they are not the most accurate things in the world, but the values they report are more or less what is reported in the BIOS and in HWMonitor, as well as the Asus monitoring software. Surely they can't all be wrong?
 
yeah just mentioning it since most people assume the m/meter is never wrong
 
I understand :)

Yes these days electronics are produced for the masses, so quality might not be as good as what it was. Might just be me who feels that way though, haha
 
Okay, so I have found a 720W Gigabyte ODIN (SHUDDER) that I can use to test with. If it works, then at least my problem is isolated and I know what the issue is
 
wabbit16 said:
Okay, so I have found a 720W Gigabyte ODIN (SHUDDER) that I can use to test with. If it works, then at least my problem is isolated and I know what the issue is
Click to expand...

The ODIN GTs are actually good. The 550watt GT is better than the 720watt Odin.
 
Qwikslver said:
The ODIN GTs are actually good. The 550watt GT is better than the 720watt Odin.
Click to expand...
So I've heard, but this is a stock ODIN. No GT on this one. In its defense, the fan looks pretty cool :p

I'll report back tonight if it worked (Holding thumbs)
 
Okay so I hooked up the 720W Odin - tested it with the multimeter and getting a solid 12.20V on the 12V rail. Much better than 10.75V. Played 3 hours of Crysis 2, Bulletstorm, Black Ops and Dirt 2 - stable as they come. Guess I found my problem
 
wabbit16 said:
Okay so I hooked up the 720W Odin - tested it with the multimeter and getting a solid 12.20V on the 12V rail. Much better than 10.75V. Played 3 hours of Crysis 2, Bulletstorm, Black Ops and Dirt 2 - stable as they come. Guess I found my problem
Click to expand...

That's quite interesting. I should remember that when I encounter an unstable PC again! Thanks for the thread. BTW does that Odin and GT both have only 1 12V rail? If not, did you balance the rails properly?
 
The non-GT ODIN has four 12V rails, 18A each. The Corsair HX650W I have only has a single rail @ 52A. I'm not too sure about the ODIN GT's though
 
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