I finally got tensorflow compiled from source and running with python3 cudnn version 5 and cuda toolkit 7.5 on the single GTX 970 that I currently have in this box.

The results are pretty awesome the training example for conv nets with mnist runs more than 25 times faster than it does on my macbook pro.

Now I am trying to decide if I should just add in a bunch of GTX 970s for the moment, because the 1080 is still very pricey.