I don't know i I'm just very unlucky or if i have RMAed the wrong parts in my system.

I have changed the graphics card two times, so I'm currently on my third gtx 970. Now i have the EVGA GeForce GTX 970 SSC ACX 2.0+ previously i had the gigabyte G1 and the MSI G4.

All the 970 cards I've had had coil whine. But the thing that irritates me the most is that the coil whine is also coming out of my monitor speakers when the 3,5mm plug is connected to the monitor and the image is sent with a DVI-DL. When i have my headset in the same connection the sound is clear.

I have contacted Asus about the monitor and they replaced the monitor threw RMA. Replacement made no difference.

I had high hopes for the SSC ACX2,0+  a new design that would address the problems customers had with the 970. But while gaming the card reaches 75 C and have coil whine (just a little less audible than the privies two cards). And from the images of the PCB it looked like the VRMs ware a different kind than the ones used on privies and outer cards.  When i got this card i also got a Display Port 1,2 cable. But when that is plugged in i cant get any sound from the monitor. The 3,5mm don't seem to be functional when the monitor is revising a DP-signal. Don't know if the SSC is supposed to carry the sound with the DP signal, but in windows i get no new sound device like i do when using HDMI. Even in Windows i can get whining / buzzing noises from the monitor speakers when i do stuff, like move the mouse cursor.

Something i also noticed is that the card "whines" after it have been used, or rather buzz. The heaven benchmark have been a worst case scenario for all three cards. When that runs a vary irritating buzzing sound comes from the card(s) and from the monitor, if the 3,5mm is plugged in. And a while after i have ran the benchmark the card sits in idle and are giving off a slight buzz.

Now that I'm on my third 970 and my second monitor i start to think the problem might lay elsewhere in my system. Can the motherboard or the PSU be causing the card to whine and the stuff that is going on with my monitor speakers?

System:
MSI Z97 Gaming 7, i5 4690k, Hyperx savage 2400Mhz 16GB
MSI GeForce GTX 970 Gaming 4G, Gigabyte GeForce G1 GAMING GTX 970, EVGA GeForce GTX 970 SSC ACX 2.0+
PSU: EVGA Supernova G2 750w
Monitor: Asus VG248QE

Thnx for the response.
I did manage to enable sound via display port. That helped with the interference with the monitor speakers.

Every thing is connected to the same outlet in the apartment. And it is not grounded. Fore troubleshooting i have ran an extension cable fro my only grounded outlet (in the kitchen) to my computer. But that made no difference. And the computer ware being grounded by the feel of the metal. When i did the troubleshooting i also tested with having the monitor and PSU on different outlets, with no luck.

Both my previous 970ies ware returned to the seller (komplett.se Swedens biggest seller of computers and parts) and they confirmed coil whine on them and granted new cards on warranty.

I have also tryed to re rout the power cables to the GPU to test fore interference with outher cables. I have also tried to disable my Mobos clean audio power function (i have a separate molex that powers the Audio PCB of the gaming 7). I have also unplugged the front audio connector to see if the interference might have come from that cable.

Running a digital audio signal to the monitor is the only thing that have had an effect.

Thnx.
Turned on "adaptive" in NVCP that healped to bring down the noice from the card a little.

But isn't the moast effective way to combat it to start messing with the voltage settings of the card?
Dont realy know what i can do. The card gets quite hot out of the box (75 C) and it have quite a bad ASIC of 68.5% so under volting might not be possible. And because of the high temps i'm not sure if over volt is a good idea..

It's probably your PSU if your motherboard is also having issues with its onboard sound. Basically, electricity from your PSU is being distributed badly because of the load of your GPU and its causing you to hear a coil whine. You may be able to rma the PSU or just buy a new one.

I have coil whine and hear it in my turtles... :'(

Thnax!
Yeah i have thout about that causing the problem. But the gaming 7 have a "separate on board sound card". I even have a MOLEX connector powering that part of the PCB. And if it was the "sound card" that got the interference then the noise would be in my headset as well, but the audio is crystal clear in those. 

I currently have a work around now with using DisplayPort. No miss-sound and i get to keep the 144Hz.
But now the screen is black every now and then when i boot. Monitor say "no DP signal". Don't even think i get the BIOS information.

If your PSU is an EVGA Supernova, doesn't it have a warranty for an RMA?  I don't know why costumer service wouldn't of suggested that...

Here are a little update on the situation.

I have had a quite a long conversation with the EVGA support team.
They have offered a RMA on both the 970 and on the PSU. Something that i naturally accepted.

I expect to have the replacements here in the beginning of next week.

Thank you for the information! +1
would a ground loop only be present on the monitor? When i use my headset in the same 3,5mm plug i get clean audio.
And if it is interference in the ground current. Will it not affect the rest of my system. Power ripples and such?

What part is at fault when this problem occurs?

i believe running unigine heaven on loop for 24 hours would help with whine it sucks till it stops. EVGA recommends 24 hours anyways. It did when i had my FTWs i cant confirmed that it was permanently fixed stepped up to FTW+ their whine was semi tolerable. never mind your talking about audio whine through speakers, that i would chalk up to a grounding issue. If you can try this, get a heavy duty extension cord and try another outlet, A uninterruptible power supply ( UPS ) might help also

Moki82
GoldenShadow,  again thanks for the information!! Alot of helpful information in your post and liknk.

On what shosin said. Do the Supernova G2 750W have UPS? I found some info on the 850W having it but on the 750 i came up blank. I did ask EVGA for a step-up to the 850W as a part of my RMA so i can only hope that they do that. Or maybe the UPS function on my 750 is broken.

A UPS is external to computer  |wall outlet|---|UPS|-----|Computer|
http://www.bestbuy.com/site/apc-back-ups-xs-1300-va-tower-ups/9307797.p?id=1218081367657&skuId=9307797
Just for example