nvidia card

I just landed my first feature edit. The film was shot on Alexa and I will cut it on FCP 7. I am buying a new Mac Pro and some bells and whistles to go with it.

What does a nvidia quadro 4000 or 5000 get me as far as editing power? Is it worth it? I have little knowledge of video cards and wondered exactly how they benefit someone when just cutting.

Also, most of my other projects are shot on RED Epic. Would the video card help there too?

Thanks.