The next tasks were
- Ensure all packages up to date with apt-get
- Ensure that python3 was ok
- Install scipy and any other relevant packages
- Install CUDA toolkit 7.5
- Install cuDNN
- Install pip3 because TensorFlow needs this
- Install TensorFlow
I installed scipy using 'sudo apt-get install python3-scipy'.
I installed CUDA toolkit using the deb(network) link, using dpkg, then apt-get.
I then went on to attempt to install cuDNN and chose the newest version (5). This turned out to be a mistake. Also cuDNN installation is confusing. In the end I installed it using the two deb packages, not manually. It puts the header files and shared libraries in the usual place but not the same place as CUDA toolkit.
Then I installed pip3 because this is the only way to get TensorFlow for linux. I followed the instructions on the TensorFlow site for linux with python3 and a GPU and everything built ok.
I needed to set the LD_LIBRARY_PATH to get python3 to find the cuda libraries.
I ran the tests on the TensorFlow page and everything seemed ok. But then when I tried to run the MNIST training example it crashed.
Eventually I found that this crash is because TensorFlow needs cuDNN version 4 not version 5. So now I have to go back and screw with the installation trying to remove cuDNN and install the older one and possibly rebuild TensorFlow.