Like the subject says, just swapped out my old GTX 1080 FTW for the 3080 and now I hear a constant high pitched tone coming from my machine. I don't think it's mechanical but maybe it's the capacitors I suppose after some quick googling. I'm not really comfortable with just getting used to it since it might cause ear fatigue and I'm using this desktop in a recording studio environment. I'm also curious if I need to run a separate cable from my Seasonic modular PSU instead of just using the single cable with two 8 pin connectors? Sorry if this is wrong forum, I didn't see a support specific board.

NVIDIA recommends - as do we - to use two separate power cables for the 3080s.

Coil whine possibly. There have been a few post on here about it and those cards.
 

EVGATech_LeeM
NVIDIA recommends - as do we - to use two separate power cables for the 3080s.

Thanks I'll pop it open for a rewire and report back if it helps.

I just installed my XC3 Ultra and I'm having a similar issue. I'm using 2 separate cables as well.
 
After playing around with precision x1 I think I was able to narrow it down to one of the fans.

Ok I'm back, after installing second power cable from PSU the sound has become slightly quieter but still noticeable. It also has a regular intermittent pattern to it like beeeeeep *pause* beeeeeep *pause* beeeeeeep *pause*. I tried penguinnss advice but fans do not seem to affect it. Precision X1 also only detects two fans? I have also recorded a video where you can hear the noise. I am trying to link a youtube video but it disappears from my post upon submission, is there a security reason for this?
 
**EDIT** Correction from earlier, I assumed coil whine was dependent on magnets in fans only not just inductors in general so very well could be coil whine. You'd think I would have remembered after being around for 1080 launch too.

And so it begins....

Yeah I'm getting the same thing, only seems to be there under load. I'm going to run a second 8 pin from my psu and see if that helps.

I'm seeing the same issue on the XC3 Ultra.  The reason you're hearing it intermittently is because the fans stop when not under load, which stops the sound.   

Tunatron
I'm seeing the same issue on the XC3 Ultra.  The reason you're hearing it intermittently is because the fans stop when not under load, which stops the sound.   

 
Actually it's constant for me as soon as I hit the power button and does not change whether under load or not. Pitch also stays the same. Also tried monitoring correlation of fans with noise in Precision X1 and there doesn't seem to be any relationship. I'd link a video if I could but the forum seems to remove it automatically.