I'm running with a Diamond HD 5870 and a HX1000W Corsair PSU.
I've noticed that when I game, a very faint but audible squeaking noise comes from my computer case. I'm pretty sure it's coil whine. In all honesty, I haven't been able to pin-point if the noise is coming from the PSU itself or the GPU, since I'm using an Antec Twelve-Hundred case and both are relatively close. The reason I think it *might* be the PSU is because I used to run with an OCZ PSU that had a very high-pitched coil whine that kicked in every time I played a game - it was so loud I could hear it clearly even while wearing headphones.
In any case, is coil whine from either the PSU or the GPU (or both) under heavy load (gaming) something I should be worried about? I've noticed the noise gets louder the higher the FPS in my games. For example, if I have Vertical Sync turned off and I load up Dragon Age: Origins, I get 2000+ FPS in the opening movie and that causes some really loud coil whine.
I've done some reading and it seems coil whine is something that seems to plague this generation of PSUs and GPUs and people claim it's a hit or miss thing - if you end up with a silent GPU/PSU combo you lucked out. Is there any truth to these statements?