The vast majority of graphics cards I've tested over years have some level of coil whine when the FPS is very high.
Agreed
Not that i'm having a go at you guys as you've been as good as you can be with my case, but who cares how common it is, it can be mitigated or entirely avoided by design and component choices.
To be told its normal on a £500 bit of hardware is an unacceptable excuse by manufacturers.