Why is it coil whine only seems to be something noticed in the last few years? I can't recall it being an issue past that period of time. Just the card complexity getting higher?
In years gone by FPS in games was not reaching crazy amounts.
So many people are still playing games using engines that are not pushing hardware, as such with Vsync off it is not unusual to have 300fps+ at this point you will get coil whine on pretty much any card.
This is why dual-GPU cards suffer it most, simply because they are capable of insane FPS in games due to raw power, all 7990's for instance suffered coil whine under benchmarking or menu areas in games simply due to the FPS. Think of it like frequency, the FPS being frequency, the higher the frequency the more audible it becomes. Hence why on a 7990 Vsync is a must, on 295 X2 AMD seem to have kept it under control somehow or they were simply built to a high standard, likewise for TitanZ, it does not seem to suffer.
I guess 295 X2 and TitanZ were never mass produced products, like just a few thousand world wide, whereas with 7990 we sold more units at OcUK than AMD have built on 295 X2.