http://www.pcper.com/news/Graphics-...-Whine-Concerns

From MSI:

The coil whine issue is not specific to 900 series, but can happen with any high end GPU and that MSI is looking in to ways to minimize the issue. If you still have concern regarding this issue, then please contact our RMA department.

From EVGA:

We have been watching the early feedback on GTX 970 and inductor noise very closely, and have actively taken steps to improve this. We urge anyone who has this type of concern to contact our support so we can address it directly.

From NVIDIA:

We’re aware of a small percentage of users reporting excessive “coil whine” noises and are actively looking into the issue.