Re: GTX 280 screeching...
Thanks everyone for posts in the thread.
I've had 3 different GTX 280 cards and 2 different 4870 cards. GTX 280 had screeching issue, 4870 had no such problem. So I thought it was the card that made the sound.
Quick examination allowed me to identify the source of noise - its the PSU!!! PSU and GTX 280 make this issue. But PSU is the one that makes that sound. My father knows a lot about electronics and he said it definitely was PSU, and he was right!
So I can only recommend everyone to try to get the best PSU you can, this might help you kill the annoying sound.
I have Zalman 850W, its super-quiet but GTX 280 makes screeching noise with it (unlike 4870).