SPCR

My motherboard makes a high-pitch whine every 5 or so minutes. I hadn't noticed it before, but since I've quietened my system, it's rather apparent.
My motherboard is Gigabyte P67A-UD3R.
I have it in a Fractal R2, but since the whine is high-pitched, I don't think the bitumen can absorb the sound?
What should I do? Put some acoustipack in there to absorb the sound?

I believe I read about some people who applied 100% silicone sealant on the coils to help with the problem. Did you search the forum for old threads on this subject?

As soon as I saw your post I immediately thought of bad capacitors. They often make that kind of whine when they blow (think hotdogs in the microwave). Even if you have solid caps on your board, the smaller sized caps are usually still electrolytic because solids don't come in capacities that small.

That said, definitely try and find out what's making the sound, as no motherboard should be whining, rather than just covering it up.

It only sometimes whines, usually after I play a game or the computer has been on for several hours.
I'm sure it's the coils, not the capacitors as the whine sound is similar to coil whines on graphics cards (if you've played Crysis, you'll know the coil whine from the opening screen).