It's nothing dangerous or defective with the unit. It's something common in electronics.
Coil whine is mechanical resonance of the coil with the frequency of the signal passing through it. Physically, a coil is just loops of wire, sometimes with a core other than air. If the frequency of the signal is in resonance with the physical wires of the coil, the coil may vibrate. Oft times, the vibration is beyond human hearing but other times it's in the range of human hearing.
I got the whine on my Gigabyte 7950 but only when FPS is really high...like above 60-70. I can't hear it while I game but sometimes it's audible when there's a static image like the one when you close the Unigine bench.
Maturity is for boring people
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