I started getting coil whine yesterday, after adjusting my fan curves. Not really sure why, but with the fans off the whine was far louder than keeping them on a low-speed minimum. It’s not fan noise blocking out the coil whine, because I still can’t hear the fans (they’re Noctua’s). I don’t know if it’s due to thermals, something to do with the power load, or what.

I’ll have to look at the polling rate thing, too - thanks for the tip.