IF it is Coil Whine there is nothing you can do since it is due to physical issues with the electronic components in high wattage hardware. Except soundproof your computer case to lessen the noise coming from it.
But I have read in the past at AMD Forums that certain drivers caused their GPU card to start having Coil Whine type issues.
So try a previous AMD driver and see if the noise goes away. If it doesn't then you would need to open a Warranty Ticket to have your GPU card replaced if it is really bad.
Most companies don't consider Coil Whine a reason to replace a hardware unless it is very bad in nature.
