My GTX 980 Ti SC+ ACX2.0+ is making annoying whining fan noise at 35-37% RPM levels. Is this normal for double ball bearings?
The sound goes away under or above 35-37%RPM. For example the fans are silent at 30% and 40% RPM
 
Here is a video I shot demonstrating this. First I have the fans running at 35% RPM and then I increase it to 40%. You can here the whining sound goes away. Then I drop the RPM to 30% and you can hear when they are passing the 35-37% mark and after that silent again. After that I set them back at 36% and leave them running there for a while. Next I put them again to 40% and then soon after to full blast at 100%. From there I drop back to 40% to beautiful silence and very soon again to 36% where the annoying whine occures again. Finally I set the fans back to auto fan control and they shut down.
 
I would appreciate very much if you guys could help me out here and watch the video. Is this normal and should I just accept it or is there something wrong with my fans?
 
I would also hope that someone from EVGA could comment on this, thank you. :)
 
Turn up your volume to hear this well. Sorry for the bad mobile phone video.
 
Here is the link to youtube:
 
www.youtube.com/watch?v=1DP-GVKyMOs&feature=youtu.be
 

Easily solved, my fans on my 980ti make this noise around 52-54%.  Set up a custom fan profile and set a breakpoint at about 33%, and set the other one at say 39% right above the one you set at 33%..(so in other words both break points should be on the same temperature) this will make it skip 34% through 38% and you will not hear the whine again.  Fine tune for best results.

Sylous
To me it sounds like a problem with the bearing system. The right fan is wobbling at that particular RPM range which might fail sometime later. It seems like 35% is the sweet spot where it vibrates the most. I would suggest replacing the card.

Not at all. No reason to send the card back it's perfectly normal. I've had 5 ACX cards and they all do this at a certain rpm. It's called phasing. Each fan is gonna have an rpm in which the counterbalance cancels out and the fan is neither positive or negative balance and this creates the hum/tone effect. It's just physics. Don't worry about your card man, if it's an annoyance just do like I said and skip those percentages in your fan profile.

This is at about 1170 rpm. The RMA replacement I received from EVGA had the same noise at that speed.
 
There are more threads about this, also see:
 
forums.evga.com/EVGA-GTX-980Ti-Fan-noise-m2436661.aspx
forums.evga.com/Kind-of-a-quotclunkquot-noise-when-980ti39s-fans-start-around-the-35-area980ti-SC-m2441737.aspx
forums.evga.com/980TI-SC-wbackplate-whistling-noise-gt-RMA-m2370410.aspx
forums.evga.com/980-TI-High-Pitched-Fan-Noise-m2402865.aspx