Correct me if I'm wrong, but don't problems like coil whine depend on who manufactured the card not the chip inside it? As in MSI, Asus, Sapphire, etc? What difference does it make if the chip inside is Nvidia or AMD?
That really depends on whether the card in question is a reference board or not. Reference boards, all of them, are manufactured by AMD and Nvidia. So if a problem exists that exacerbates coil whine, the problem begins with the design/engineering procedure at AMD or NV. Now it is entirely possible that some manufacturers take additional steps to "remove" coil whine -
there are in fact things that can be done to minimize the noise or prevent it from being perceptible to human ears. Presumably, some manufacturers do this, some do not. I do think nvidia tries to prevent it at the source, with the design of their ref boards. The facts are, though, that there are more end user reports of coil whine with AMD cards than there are with NV 700 series cards. Who the fault lies with isn't completely known but for anyone that has studied statistics, samples are representative of populations so if x% of 100 users report coil whine with a certain brand of 290 card and y% of 100 users report coil whine with a GTX 780 card, that's probably representative of 100% of all cards, or the entire population, of the market. Like I said - generally speaking, customer satisfaction is higher on the NV end with less reports of coil whine. I actually don't think i've seen any newegg reviews mention coil whine with any GTX 780. The last reference nvidia card I heard with a few reports was the 670, but i'm not sure if that was the ref version or not. Have not seen any reports with 700 series.
Some people will happily use vsync (if it works, it doesn't always) to prevent coil whine. Some cards whine even with vsync. And if you're using lightboost 144hz, coil whine doesn't matter whether vsync is on or off and you just have to RMA the card. Coil whine also varies in terms of how audible it is - sometimes it is barely audible, while other cards have RIDICULOUSLY loud coil whine. The dual-X 7970s I had briefly, had INCREDIBLY loud coil whine. It was unbelievable. I mean, if it's not perceptible I don't care. But if it's loud, screw that - RMA time.