Are these numbers indicative of a bad PSU?

kellehair

Member
Nov 26, 2005
110
0
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The PSU in question is an Antec NeoHE 550W. According to SpeedFan my voltages are as follows...

Vcore1 (CPU): 1.41V (BIOS is set to 1.45V)
Vcore2 (RAM): 1.94V (BIOS is set to 2.2V)
+3.3V: 3.31V
+5V: 4.95V
+12V: 2.94V (that's not a typo)
-12V: -16.97V
-5V: -6.01V
+5V: 5.32V
Vbat: 3.12V

I don't know the first thing about power supplies but this seems bad. I've recently fallen short on a few OCs and thought this might be the problem. What do you guys think?

Intel E2140 @ 3.0GHz (8*375)
Gigabyte GA-P35-DS3L
SuperTalent 2x2GB DDR2-750 (4-4-4-12)
Seagate 7200.10 320GB
eVGA 8800GT (730/1800/2020)
Antec NeoHE 550W
Antec P180
XP Pro x86 and Vista Ultimate x64
 

Billb2

Diamond Member
Mar 25, 2005
3,035
70
86
Try another program for reading voltages, like Sisoft Sandra or Everest.
With the 12v output at 2.94 volts, I doubt the computer would work.
 

myocardia

Diamond Member
Jun 21, 2003
9,291
30
91
Originally posted by: Billb2
Try another program for reading voltages, like Sisoft Sandra or Everest.
With the 12v output at 2.94 volts, I doubt the computer would work.

With the 12v @ 11v, the computer wouldn't even boot. Use a digital multimeter, and check your 12v voltage. Just use a spare molex connector, and you can check both the 5v and 12v rails, in just a few seconds.
 

mpilchfamily

Diamond Member
Jun 11, 2007
3,559
1
0
All software readings of voltages are Wrong. Do not trust software readings. If you want to check the voltages then use a volt meter and check the voltages threw an unused connector. The yellow wire is the +12V and the black wire is the ground. Anything within +/- 5% of the rated voltage is within spec. So if the voltage is higher then 12.6 or lower then 11.4 then you have a problem. If the voltages are actually out of spec then you would be experiencing many problems.
 

kellehair

Member
Nov 26, 2005
110
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0
Thanks guys. Sandra gave me the same results so I broke out the old multimeter. The 5 and 12V rails were perfect, even under load.

Now my questions is, does this prove my that PSU is good, or could there be other problems? For instance the voltages set in the BIOS do not seem to be recognized at the same levels in Windows.
 

jonnyGURU

Moderator <BR> Power Supplies
Moderator
Oct 30, 1999
11,815
104
106
Originally posted by: kellehair
Thanks guys. Sandra gave me the same results so I broke out the old multimeter. The 5 and 12V rails were perfect, even under load.

Exactly.

People need to remember....

SOFTWARE IS USELESS FOR CHECKING VOLTAGES!!!!!!!
 

Sheninat0r

Senior member
Jun 8, 2007
515
1
81
Actual voltage could be lower than BIOS-set voltage because of vdroop - on some motherboards, pencil mods can fix this, or you can just up the voltage until you get what you want.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
The problem is the chips that do the monitoring can be located anywhere on the board. They could be measuring the voltage through resistors, tiny traces run half way around the board and add to that the accuracy of the chips themselves isn't high.

I use the onboard voltage measurements to tell me if there is something there or not, but not the accuracy of it.

For that I built a custom circuit around a couple pic micros to give accurate info.
 

jonnyGURU

Moderator <BR> Power Supplies
Moderator
Oct 30, 1999
11,815
104
106
Originally posted by: Modelworks
The problem is the chips that do the monitoring can be located anywhere on the board. They could be measuring the voltage through resistors, tiny traces run half way around the board and add to that the accuracy of the chips themselves isn't high.

I use the onboard voltage measurements to tell me if there is something there or not, but not the accuracy of it.

For that I built a custom circuit around a couple pic micros to give accurate info.

Exactly.
 

Danzilla

Platinum Member
Dec 30, 2000
2,747
0
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So, NONE of the software tools for checking PSU voltage are any good? :p why do they even show them then.

I was just trying to figure out why SiSoft Sandra was reading my 12v+ as 10.3 constantly, eventhough in bios it say something normal, like 12.14. (also reading Vsb anywhere from 1.0 - 4.4)