BUZZZZZ SOUND

I have a buzzing sound comming from my GFX card, i never noticed it before but with my last overclock I notice it now, even after i turn the OC back down i notice the buzzing sound. Its not comming from the HS/Fan but from the card itself. It is a HD3870 Gigabyte, is this normal?

Normal, no. Bad, not really. I've had CPU's making whining sounds before, as well as GPU's, and its never been a problem.

Happens with some hardware, graphics cards, PSUs etc. Its usualy in the range that only younger people can hear (re:mosquito ring tone) it seems.

it's caused by small electronics resonating with a certain frequency, like inductors and i think clock generator crystals.