An Applied Investigation Into Graphics Card Coil Whine 111
jones_supa writes We all are aware of various chirping and whining sounds that electronics can produce. Modern graphics cards often suffer from these kind of problems in form of coil whine. But how widespread is it really? Hardware Canucks put 50 new graphics cards side-by-side to compare them solely from the perspective of subjective acoustic disturbance. NVIDIA's reference platforms tended to be quite well behaved, just like their board partners' custom designs. The same can't be said about AMD since their reference R9 290X and R9 290 should be avoided if you're at all concerned about squealing or any other odd noise a GPU can make. However the custom Radeon-branded SKUs should usually be a safe choice. While the amount and intensity of coil whine largely seems to boil down to luck of the draw, at least most board partners are quite friendly regarding their return policies concerning it.
Mac Pro 2013? (Score:1)
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It's a desktop.
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The point is that the laptop uses laptop parts whereas the MacPro uses server and workstation parts.
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What good are server components when they aren't in a server chassis?
They are good for having many cores for the multi-threaded applications the MacPro is built for. I'm pretty sure server components perform exactly the same regardless of the chassis.
The Mac Pro is marketed as a "workstation", but it's basically a mid-range desktop.
LOL. Oh please do link me some of those "mid-range desktops" using Xeons, ECC memory and FirePro GPUs. I won't hold my breath, though.
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So?
So to what? The entire point is that the MacPro is not a laptop because it doesn't use a single piece of laptop components. That is the point in and of itself.
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That should be amended to dual FirePro GPUs.
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No idea why you were modded troll, I wanted to somewhat disagree with you - the GPU aren't really "desktop", they are on custom boards a bit bigger than on laptops but smaller than on desktops. Funnily you will have a harder time replacing them, compared to an MXM laptop GPU board which at least follows some standard. You won't be able to get one from somebody else than Apple, and that would be on their terms such as handing your Mac over to an Apple shop and have them upgrade it for you (if they even agree
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the GPU aren't really "desktop", they are on custom boards a bit bigger than on laptops but smaller than on desktops.
Yes they are. FirePro GPUs are workstation graphics cards.
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FirePro is a driver. You even have an APU variant http://www.sapphirepgs.com/pro... [sapphirepgs.com]
In fact if we want to go all pedantic and nerdly, the Fire Pro variants on these Mac are said to be not such much Fire Pro as the drivers are specific to OS X and less featured. CAD, engineering etc. mostly happens on Windows.
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A difference is Mac Pro uses a Tahiti GPU (on D500 and D700) which you won't find in any laptop.
We would have to go back to the "sewing machine" or "oscilloscope" form factors of the 80s.
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Silly rabbit. Even Sarah Palin knows that the leader of Canada is a Premier, not an emperor.
My nvidia card started whining after lightning (Score:1)
Motherboard got fried by lightning, replaced said motherboard, video card now whines.
I've gotten used to it.
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I used to have a Sound Blaster Pro which had some lightning damage. Something on the board had turned microphonic, and you could shout at the card and hear it through the line output.
Fun stuff.
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Chances are it's the PSU causing it. That seems to be in at least my experience over the last 20 years, that if you're experiencing some type of coil whine it's related to the PSU--usually a weak rail, or a rail that's failing. This is especially true under heavy load, there are rare cases as mentioned in a lower post of other issues causing it but the majority of the time it's something you can fix on your own. Especially if it happened after a strike.
The Cause (Score:5, Informative)
I've designed lots of these little switch mode supplies. (SMPSs)
The noise comes from the inductors. Inductors are coils of wire around a ferrite. When the current changes through the wire, the wire physically expands and contacts from every other wire. This is the source of the noise. (SMPSs normally switch from 200kHz to 2MHz, so well outside our audio range)
There are a few things a designer can do.
1. Encapsulate the coil. This holds the wire tighter together and can minimise noise, but is only usually used in large inductors like those in invertors for UPSs or solar.
2. Eliminate subsonic oscillation with good multi-pole compensation. Switch mode power supplies have, have first second and third order responses which require filters to damp them. If you don't design these filters well, you can get subsonic oscillation which falls into the audio band. The power supply still regulates OK, but you can get that annoying whine.
3. Occasionally the noise can also come from a periodic load with that falls into an audio range. More capacitors on the output can help that.
Also, very very occasionally, it can come from ceramic capacitors that use a high k dielectric that are microphonic, but in my experience it is usually the capacitor acting as a microphone that upsets the circuit.
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Actually, it is slope compensation that you want to use to avoid subharmonic oscillation, and you can avoid that need entirely by designing your SMPS such that it never exceeds 50% duty cycle for the design load.
Re:The Cause (Score:5, Informative)
AC is correct. Most forms of subharmonic oscillation are caused by slope compensation issues, but pole filtering can also be an issue . For those who want the nitty gritty details, see this. http://www.ti.com/lit/ml/slup2... [ti.com]
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Have you ever noticed if this effect gets better depending on the shape? I use transformers in audio amps I build, and often there's a marked difference if I use R-core over EI or Toroid. But this is signal noise and not physical noise. If the transformer is making physical noise, I'd never be able to hear it over my guitar solo :-p
Re: The Cause (Score:3)
Slashdot no longer the place you used to go?
While it's a bit more mainstream audience than back in the day... you still get great comments like this one from time to time.
So when you think Slashdot is dead, remember this post.
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I would also like to thank Hardware Canucks for doing this test in the first place. Like most nerd/geek/freaks, I'm very sensitive to noise, and computer case noise is the worst because you will probably have it for the life of the box...that you use for 10 or 15 hours a day, every day.
So, thanks. And thanks.
BTW, it would be kind of awesome if the computer hardware testing sites incorporated sound tests into their general testing of stuff.
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BTW, it would be kind of awesome if the computer hardware testing sites incorporated sound tests into their general testing of stuff.
You mean like this:
Tom's Hardware: Sapphire's Vapor-X R9 290X 8GB - Temperature, Noise And Power [tomshardware.com].
Actually I continuously get frustrated by "enthusiast" computer sites reviews who seems to being entirely lacking in technical knowledge when it comes to anything beyond quoting the manufacturers press material. Half of them might as well have a companion site reviewing shoes and fashion tends given their display of technical ignorance.
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Indeed. There are people here that know their stuff.
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Naïve question maybe, but couldn't some sort of lacquer be applied on wires to prevent them from physically moving?
For small gauge magnet wire, it often is used on better, but it is not perfect.
Better components tend to cost more, which for commodity priced* products like video cards, saving a few cents can be considered worthwhile.
*) A lower bill of materials cost, can be used to past on some or all of the savings to the consumer, where for price sensitive consumers, the company with the cheapest product can end up selling potentially 30-400% more if you have the cheapest of a seemingly similar product (video card wit
Re:The Cause (Score:4, Informative)
When the current changes through the wire, the wire physically expands and contacts from every other wire.
Not just the wires. But the core physically changes shape due to magnetostriction [wikipedia.org]. The only was to reduce this is by careful selection of the inductor magnetic material and/or reducing the flux density in the core.
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Or cover it with goop.
Re:The Cause (Score:4, Interesting)
Full disclosure: I worked on this *exact* issue at NVIDIA for a brief period, although several generations ago. Usual disclosure applies - the below is my opinion, not theirs.
It doesn't surprise me that the NVIDIA reference cards do pretty well; they took the issue as seriously as some of their customers do. We made some fancy measurements to evaluate different methods of reducing the noise; indeed, some of the "common sense" things a designer can do are actually wrong. For example, #1 from the parent (fill the inductor package with something to keep the coil from moving) isn't necessarily a good idea. In some cases, that actually makes the vibration *worse*; rather than prevent the coil from moving, it helps transmit the motion of the coil to the PCB, which can then act like a sound board, making the tiny coil's vibration into something audible. (The sound board is the part of a musical instrument that is forced by the string to vibrate, making sound. It's what makes an acoustic guitar make noise when a string is plucked, while an electric guitar is relatively silent with no amp.)
That's not to say that encapsulation is a bad idea necessarily - just that this is a much more difficult problem to solve than you might imagine at first glance. And something that works well for a particular application/GPU/inductor/card combination might not work as well for a different combination.
A long time ago, I had a PowerBook G4 that had a buzzy whining that I later (while working on this problem) learned was from the inductors. I discovered that by using the CHUD Tools part of Apple's developer tools to disable the "Nap" option (this is the CPU Nap power-saving mode, not the much more recent "Power Nap" marketing-branded feature), the whining would go away, because the current in the inductors was much closer to constant.
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Header - surprisingly, AC current on a regular wire heater. The coils of heating element do act like an inductor and cause it to vibrate some. Depending on the mount, that vibration can translate into actual vibration of the chassis causing the buzzes.
LCD monitor - the switch mode power supply is generally the cause of it. Practically everything with a SMPS is vulnerable to buzzes/wh
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There are a few things a designer can do.
1. Encapsulate the coil.
Is this a thing I can do, say, with epoxy? Do I have to worry about heat?
Anybody familiar with the manufacturing side? (Score:3)
Does anybody know if that just adds too much cost, without performance benefit, and so gets cut during the BOM penny pinching? Do potting compounds have properties that degrade the performance or efficiency of common magnetics? Why is it that, if coil whine is an issue, they aren't just dipping the things in epoxy and calling it a day?
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Because 99.999% of users don't care enough to complain. When you get enough whine that a sizable number of users scream bloody murder, something gets done. But for a more typical amount of supply whine, why spend the extra buck or two? And chances are, it never makes it to the BOM penny pinching stage, because unless the design is producing serious noise, corrective actions probably won't be taken in the first place.
Besides, assuming you use a standard-shape power supply, the users who really care about
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The issue is the "PSU" on-board a big graphics card is not replaceable. It's power cirtcuitry that feeds on the order of 200 amps to the GPU and handles huge transients / power and voltage transitions.
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Ah. I missed the fact that you were talking about inductors on a DC-DC converter on the graphics card itself. In that case, yeah, that's just shoddy. On the other hand, it is easy to fix:
:-)
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As for quoted amperages, high end graphics cards get
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Me too, but I'll try anyway. After all, this is Slashdot. :-D
If I understand correctly, a buck (downstep) converter starts with an oscillator that drives a transistor. The transistor turns the power source on and off very rapidly. An inductor between the high source voltage (after the switch) and the low-voltage output effectively turns the resulting current cycling into a voltage drop, and a capacitor smooths the resulting power supply
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The issue is the "PSU" on-board a big graphics card is not replaceable. It's power cirtcuitry that feeds on the order of 200 amps to the GPU and handles huge transients / power and voltage transitions.
Perhaps you mean 200 Watts?
Re: Anybody familiar with the manufacturing side? (Score:2)
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None. But there are many conductors instead.
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200 amps was on the provocative side. but about par for a Radeon R9 290X in the "uber' profile or overclocked.
100 amps is routine on a CPU : 125 watt and 130 or 140 watt models or even more for a few ones. It has hundred pins, around a thousand to connect it to the motherboards, most of those are ground and power.
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Because 99.999% of users don't care enough to complain.
That would mean 1 / 100,000 users complain. I think more users care. 99.99% or even 99.9% might be a closer value to the amount of users that don't care.
Of course I'm just nitpicking and past your point, but there's a surprisingly big difference into how many 9s you slap there. :)
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I guess it depends on how bad the noise is. I could believe one in 10K or one in 100K. I'd have a hard time believing that a manufacturer would ship something with enough noise to bother one in 1K people. Usually I'd expect the noise to be in a frequency range where most adults either can't hear it or can barely hear it.
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"I guess it depends on how bad the noise is"
Noise is relative.
We're putting systems on desktops with near-silent PSU, chassis and CPU fans along with SSDs for booting, but can't quite justify the spend required to put 4Tb (local scratch space for scientific computing) on SSD (you can only do so much inside a $2k/system budget.)
As a result we've had a couple of people complain about "electrical arcing noise" from their computers, which turned out to be headseek noise when they're grinding on large datasets.
Re:Anybody familiar with the manufacturing side? (Score:5, Informative)
I understand that high-frequency magnetics are at risk of physical oscillation(the detailed math is right over my head; but all it takes is one part of the part attracting or repelling another part of the part, at least under some input waveforms, and you'll potentially see movement, which easily enough turns to sound); but the seemingly obvious solution is just to pot the magnetics in an adequately thermally conductive epoxy or other encapsulant.
Does anybody know if that just adds too much cost, without performance benefit, and so gets cut during the BOM penny pinching? Do potting compounds have properties that degrade the performance or efficiency of common magnetics? Why is it that, if coil whine is an issue, they aren't just dipping the things in epoxy and calling it a day?
Unfortunately mechanical damping of the inductor vibration isn't as effective as simply reducing the amplitude of driving frequency in the audio bands. Remember this is a sub-harmonic that is being excited by a non-linear coupling to the audio frequency. Basically the energy in a higher frequency is being converted into a lower audible mechanical frequency.
Theoretically, simply changing the mass of the physical oscillation (e.g. cementing it to something heavier) only slightly modifies the frequency of the oscillation (potentially creating more audible noise) and it still doesn't change the energy much. Viscous damping of the mechanical frequency might help a little bit more. Unfortunately, in practice, surrounding things like solder joints in potting compounds is risky as they have a different thermal expansion coefficients and it can cause additional mechanical stress (resulting in reduced mechanical reliability).
In the end, mechanical means are still not going to be as effective as changing the circuit to reduce the amount of switching energy frequencies which are coupled to the audio frequency bands. Probably even from a total system cost point of view...
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"but the seemingly obvious solution is just to pot the magnetics in an adequately thermally conductive epoxy or other encapsulant."
As another poster noted, this can make things worse, especially if the epoxy is rigid.
Some of the best methods involve potting _part_ of the coil (wax drops) or using rubber o-rings to absorb the motion/sound. The issue then becomes that those parts have to pass thermal energy in order to avoid melting.
Acoustic noise control in switchmode circuitry is an engineering discipline a
To me this is good news (Score:1)
I always though the noise from coming from a cap that was ready to explode.
Re:To me this is good news (Score:4, Interesting)
Like bearing noise in a full-throttle jet engine (Score:3, Funny)
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Return Policies = enjoy that refurbished card! (Score:2)
ug.. Coil whine happened to me a few years ago on a brand new card so i RMA'ed the card. At the time it took some convincing to issue the rma too iirc. They shipped me some refurb card that never worked right. And the next one didn't work right (unstable or just plain DOA cant recall). By now Im up to 40 bucks just in shipping these crap cards back to the company. Never did get a working card out of it. The next ca
damn right! (Score:1)
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You're talking about more than double the generally accepted maximum frequency for human hearing. You're solidly into the ultrasound range. Other animals can hear at those frequencies [wikipedia.org] (such as cats), but I don't see the evidence of any human ever having that hearing range.
TL;DR: Citation needed.
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I think the AC is talking about beat frequencies...
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You need two interfering frequencies for a beat frequency and what you're hearing is the difference between the two [wikipedia.org] (their physical interference)--not the 42 kHz tone itself. The audible frequency is still going to need to be within that 20 Hz - 20 kHz (roughly) window in order for a human to hear it.
TL;DR: Citation still needed.
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I have an EVGA GTX 560Ti . My wife finally made me replace my fans.
They used really cheap fan mounts that vibrate like heck whenever they spin up.
Just replaced the stock fans with this rig today: http://www.amazon.com/Titan-Ad... [amazon.com]
Much quieter now.
Security? (Score:2)
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