Components causing PSU to whine

[mda]

Hi all,

I've just stumbled across something interesting regarding PSU coil whine.

So my new build's PSU started to whine. I have clearly isolated the sound to the PSU, by removing it from the case and listening in on the motherboard/other components.

Annoyed, I tried swapping in a PSU from another system that had no such problems.

Then for some reason the PSU begins whining in exactly the same way as the first 'problematic' PSU.

Is there any explanation for this? I always thought that the PSUs did whine, but never realized that the components themselves could cause PSUs to exhibit this kind of behavior.

Now to return all the PSUs to their original rigs :/

 

[drescherjm]

My understanding is the power load of the system causes the coils of the power supply to vibrate. Depending on how much load (lesser or greater) you apply the vibrations will may become more in the audible range.

 

[dandragonrage]

Then for some reason the PSU begins whining in exactly the same way as the first 'problematic' PSU.

The problem is typically with coils (inductors or transformers, often the flyback transformer when the problem is in a TV/monitor) which when not specced/built correctly can resonate such that they physically vibrate (sometimes called "ringing") under certain conditions. This can typically be fixed by replacing the coil with a heavier coil (using thicker gauge wire) and/or coating the coil in epoxy to help keep it solid. Other components can somewhat do this as well, typically those which use very thin wire gauge for the leads, but coils are by far the most common cause (some people think the problem is with capacitors, and while again yes they can do it, they do so FAR less than coils). A main part of the reason they do this is that no matter how good your power supply, none are perfect enough to completely eliminate voltage fluctuations from the AC power and the switching frequency of the power supply, and that little bit of noise/ripple is a factor in causing ringing. Also, some of the coils in a power supply are always going to be exposed to AC anyway, since they are partially responsible for converting the AC to DC to begin with, so it can't be fully eliminated. All that can be done is to reduce AC noise/ripple as much as possible with components that are heavy duty enough, and to use a switching frequency not likely to resonate with the components you use. It's a very complex issue, so it's sometimes regarded as partially an "art" to get it right (though technically it really is all science), and some manufacturers do it better than others. Some (Seasonic) repeatedly fail.

Sometimes adjusting the load can change or even fix the problem, but the best solution is to swap power supplies to something made by Super Flower instead of Seasonic. Reviewers and self-proclaimed PSU experts on this site repeatedly claim that this problem is so uncommon that it should be disregarded, even though reviews of Seasonic on Newegg, manufacturer forums, and here are far disproportional in their coil whine complaints.

 

[Nicartis]

I had a coil whine issue with an Antec NeoHE 500w PSU after my rebuild last year (the power supply was 5+ years old). The coil whine would happen sporadically when gaming and on certain game menu screens where the fps went really high...normal desktop use it was silent and this PSU was silent in my old Q6600 PC.

I tried several things to get rid of it but ultimately nothing worked until I replaced it with a Seasonic m12ii 620w. Now the rig is silent 100% of the time. Swapping it out is the best option imo.

 

[coffaholic]

I had whining problems that were a pain to get rid of and quite frustrating at that. It would only happen when both the cpu and gpu were loaded regardless of changing voltages for both pieces to try to switch the power envelope to one that wouldn't whine.

EVGA 560ti + pc&p 750w silencer = psu whine.
Swapped gpu->
EVGA 670SC + pc&p 750 silencer = gpu whine.
Swapped psu->
EVGA 670 SC + seasonic x1050 = psu whine
Rma'd gpu->
EVGA 670FTW + seasonic x1050 = silence.

It seemed to jump around everywhere until I found the hardware that would play nice together.

 

[mda]

Hm. So it looks as if the power load I'm giving the PSU makes it whine. Maybe it has something to do with Haswell's power saving state. I notice that when the CPU changes between clocks, the frequency of the whining changes.

WTB> GTX 480s?

I guess I'm hoping that some overclocking, as well as getting my next GPU will change my load characteristics significantly enough that the whine disappears.

 

[dandragonrage]

Yeah, it often varies with the load of the PSU and some have reported that disabling all sleep states but C1E (or sometimes even C1E) fixes it, but that's not even close to a valid option IMO. So I have to significantly raise the electric cost of my PC to fix the problem with your product that you refuse to fix, Seasonic? F.U. That was actually suggested to me for my Seasonic which whined. While upgrading from 80plus to gold or silver (F bronze) didn't seem like a worthwhile move when I had power saving sleep states enabled, it sure seemed the right move when I had to compare 80plus w/o sleep states to 80plus gold w/ sleep states. I don't recommend Seasonic anymore because they refuse to give a s*** (several generations and they haven't even tried to fix the issue). Super Flower all the way. I run a Rosewill Capstone now. Great PSU, no whine. Kingwin LZP is a good line too also Super Flower.