Hhahaha, I thought I was crazy and no one would pay attention if I tell ppl that my GPU on my grafx card itself is emitting high frequency noises!!
I have it too. Though I have to add, that I also found other games that do it, and sometimes, when there are many apps and windows oppened in my windows-gui it also starts to squeal. When I press the mouse button, it stops. Its also depending on where the mouse cursor is.
The noise can be a pain, as its a very high frequency...maybe 17-18k I would guess.
I also have an AMD + ATI, but an older card, the 9800Pro patched to 9800XT.
The other day I played a game in window mode (I dont know which anymore, maybe it was even DW) and when the mouse cursor was inside the application it made a low frequency noise, and the more I moved the mouse cursor closer to the edge of the window, the more the emitted noise's frequency tuned down, until the cursor left the window and was on desktop, where the noise jumped into a high frequncy again (exactly when the mouse cursor crossed the application windowborder. )
So when moving my mouse in and out of the window it sounded really odd.
At least I am not crazy. Maybe I should sue ATI...causing me headaches and maybe sending other unwanted wavelength into my body (I sit rather close to my pc with open case)
At least I now know I m not alone.