title: Confusion about Installation Requisite for TensorFlow
body: <p>I am now maintaining a legacy project which utilizes <code>tensorflow-gpu-1.11</code>. According to this <a href="https://www.tensorflow.org/install/source#gpu" rel="nofollow noreferrer">link</a>, this package is associated with some particular versions of <code>gcc</code>, CUDA, and cuDNN</p>
  <pre><code>Version                 Python version  Compiler    Build tools     cuDNN   CUDA
  ...
  tensorflow_gpu-1.11.0   2.7, 3.3-3.6    GCC 4.8     Bazel 0.15.0    7       9
  ...
  </code></pre>
  <p>Therefore, I think I need to</p>
  <ul>
  <li>Step 1: set up system compiler to <code>gcc-4.8</code>, perhaps using <code>sudo update-alternatives --config ...</code></li>
  <li>Step 2: install CUDA 9.0 and associated cuDNN 7</li>
  <li>Step 3: creates a virtual environment and <code>pip install tensorflow_gpu==1.11.0</code></li>
  </ul>
  <p>However, an alternative way to install this package is by invoking following command in the <code>conda</code> environment</p>
  <pre class="lang-sh prettyprint-override"><code>conda install -c anaconda tensorflow-gpu=1.11.0
  </code></pre>
  <p>which, <strong>contrary to the official requirement</strong>, tries to install higher versions of <code>cudatoolkit</code> and <code>cudnn</code>, as shown below</p>
  <pre><code>The following NEW packages will be INSTALLED:
  ...
    cudatoolkit        anaconda/linux-64::cudatoolkit-9.2-0
    cudnn              anaconda/linux-64::cudnn-7.2.1-cuda9.2_0
  ...
    tensorflow         anaconda/linux-64::tensorflow-1.11.0-gpu_py36h9c9050a_0
    tensorflow-base    anaconda/linux-64::tensorflow-base-1.11.0-gpu_py36had579c0_0
    tensorflow-gpu     anaconda/linux-64::tensorflow-gpu-1.11.0-h0d30ee6_0
  ...
  </code></pre>
  <p>I am not sure if I understand the installation requirements correctly. If not, hope someone could help on the right track.</p>