I have a ViewSonic VP2770-LCD monitor and an NVIDIA GeForce GTX 780 graphics card connected via DisplayPort. It is capable of displaying 32bit 10bpc color but on all of the test images, I have used it is not doing so. I have a digital camera that can make use of this and I want to.
I believe the consumer series of that time at least only would output 10bpc in supported DirectX applications, not normal desktop applications. Might take some research to uncover exactly what is supported.