I have an AMD 7970 and I am using Maya 2014 in Windows 8.1 and it works fine. I don't know about any nvidia card since i don't have any.
What I want to say though, is that you should enable the Viewport 2.0 rendering viewport with DirectX 11 NOT with OpenGL. The performance difference is quite big.
To do that go to: Window>>Settings>>Preferences>>Display>>Viewport 2.0 rendering engine: DirectX 11
Then restart Maya. Once you get back in, go to your viewport menu: Renderer>>select Viewport 2.0
It should now say "Viewport 2.0 (DirectX 11)" at the top of your viewport
A small example about the performance difference is the following:
1. When moving a selected object of ~25K polys with shaded mode. DirectX 17-18fps, OpenGL 6-7fps (i had it focused)
2. When moving an entire scene of ~50K polys with shaded mode: DirectX 90-120fps, OpenGL 50-60fps (i had it zoomed out)
By the way my 7970 is XFX Double-D, and i do not recommend it at all (don't buy an XFX ever, they have the lowest ASIC quality). If possible do try and buy the Sapphire R9 290 Tri-X or at least the Sapphire R9 280 Toxic, both of these cards have the Tri-X cooler which is the best air cooling solution at the moment (for a GPU), plus Sapphire is at the same quality level as MSI i believe (regarding ASIC quality, seen in GPU-z)
Cheers!