12V Rail Voltage

Darg

Darg

Darg

Soldato
Joined
6 Sep 2006
Posts
6,302
Location
London
Ok just a simple question really.

I have the Truepower 2.0 550W PSU that came with my case. Now this has gotten excellent reviews everywhere I've looked and neoseekers review included a test that showed the 12V voltage level as 12.16V on idle and 12.15V on load. Now I just installed SensorsView and this shows my 12V voltage as 11.4V. This is completely constant and I haven't seen it change through several reboots.

When I check in BIOS my 12V is shown as 12.08 or something close to that. What I am wondering is could my poor motherboard cause the lower voltage levels? This may not be possible as the motherboard never comes in to the circuit between the PSU and the components. Perhaps it is simply a sensor error with the motherboard?

What I am wondering is could me cable setup be causing this low voltage level? The PSU has a "Fan only" cable that I have my 120mm and 2x80mm case fans attached to. This doesn't supply enough power to the fans to have them running full and they only seem to run at half speed like that. That's perfect for me though as it sounds like a vacuum with them all on full even if it does drop CPU temps by 5C.

Would this be affecting the 12V rail voltage? I also have a small PCI slot extractor fan attached to the cable that feeds the AGP graphics card. Would this be causing problems?

I have 3 PATA hdds and 1 DVD drive that all run off the other cable line. Would the amount of devices on that line affect the voltage levels?

And possibly most importantly could these relatively low voltage levels on the 12V rail be causing problems? I have some minor stability issues such as occasional stuttering but I put that down to my poor Asrock motherboard.
 
The only way to be really sure of voltage levels is to use a multimeter (unless you get specialist tools but they cost more than a multimeter), motherboard readings are inaccurate in many cases.

Low 12v levels could cause instability issues but I wouldn't go on what the software is telling you right away without checking further. :)
 
hrm well the only shop selling a multimeter ive found are selling them for €35. I want one to check other volts on the board but until I can afford that I guess I'll just have to trust my BIOS rather then my mobo sensor.
 
A multimeter shouldn't cost more than £10 (~€17 last time I checked exchange rates) for a cheap one so I'd suggest having a quick look around further but the bios is more likely to be correct I'd think. :)
 
I've spent countless hours worrying about voltages and even swapped out my PSU only to see the same dodgey readings.
My advise is ignore just about every prog/reading you get and just buy a multimeter. It'll save you worry and time and probably money.
Your Bios is what to go on till you buy a multimeter but don't stress over prog readings.
 
Ok thanks a million guys. I was worried I had a dodgy PSU for a while as all reviews of the Truepower 2 gave 12V+ actual voltage on the 12V rail.
 
mishima said:
Have a check of this that Wayne gave a quick review on other day: http://forums.overclockers.co.uk/showthread.php?t=17706993
Click to expand...

That's quite a nice tool indeed. Most people are put off by measuring voltages by putting the pins on certian parts of the motherboard, but that tester looks easy, and is fairly cheap. Sure, most people won't think it's for them, but for system builders, looks like an awesome tool.
 
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