More details in my blog post at https://aws.amazon.com/blogs/aws/new-amazon-ec2-instances-wi...
https://github.com/tensorflow/tensorflow/releases/tag/v1.4.0...
All our prebuilt binaries have been built with CUDA 8 and cuDNN 6.
We anticipate releasing TensorFlow 1.5 with CUDA 9 and cuDNN 7.