Ameliorating GPU Coil Whine
GPUs are not made the same, with differences in PCB layouts and components that can result in slightly better or worse performance. One other aspect that comes with different GPU PCB implementations is coil whine or rather how severe it can get.
Coil whine is a permanent issue and the only way to truly solve it is to simply get a different GPU. If that is not an option for you then you can try different steps to ameliorate the annoying buzzing noise coming from your GPU.
When Do You Get Coil Whine
As the name implies coil whine on a GPU happens when the part is under load or is pushing high FPS leading the power delivery components to work harder producing electrical noise and vibrations. The severity of the noises depends on the GPU power limits, PCB design, the quality of the power delivery components, etc.
GPU Undervolt
The very first partial solution to this auditory trouble is to undervolt the GPU, effectively allowing the power delivery components on the GPU PCB to work less. A proper undervolt will lead to less coil whine, better temperatures, and lower fan RPM while delivering identical performance.
Undervolting is quite simple as well, just make sure to use heavy GPU benchmarks to ensure no clock stretching is happening and the GPU is performing as expected. If you did prior optimizations like forcing P0 or custom GPU BIOS you need to revert those first before you try undervolting your card.
FPS Cap
Another step that can be complementary to undervolting is limiting the FPS in your games. You will notice that coil whine is most noticeable when you are playing competitive games at 300+ FPS. By limiting FPS for your games to a slightly lower value you can limit the coil whine.
FPS caps can also work in casual games since the load on the GPU is lower and the power delivery components do not have to push as much voltage.
IEMs
Replacing your GPU might be costly while replacing your headphones is quite a bit cheaper. If you want to eliminate coil whine, and essentially any other noise, you can use IEMs instead of headphones for better sound isolation.
This might be a silly solution but since you cannot fix the root cause without changing the card this can be an acceptable solution for many gamers.
TL;DR
High-performance GPUs often come with coil whine and since you can’t fully get rid of it you can try: undervolting the GPU, capping your FPS, or using IEMs for better sound isolation.