i updated the bios of my GPU though, or flashed not sure whats the difference but i got it from gigabyte website. Before that, the card was not working properly with BF3 kept crashing and the update fixed it. Could that cause the coil whine?
Could be. I have a gigabyte 560soc and all the official stuff from gigabyte ( bios flash update, drivers ) but did install later on driver 285 and then got that ( probably ) same high pitched sound when i ran a stresstest or played demanding games. I went back to 266 because with 285 i have issues with stability. ( gigabyte soc's are pretty picky with drivers )
I believe i never heard that sound again after that, not sure though, have to test that.