title: How to run Tensorflow on CPU
body: <p>I have installed the GPU version of tensorflow on an Ubuntu 14.04.</p>
  
  <p>I am on a GPU server where tensorflow can access the available GPUs.</p>
  
  <p>I want to run tensorflow on the CPUs.</p>
  
  <p>Normally I can use <code>env CUDA_VISIBLE_DEVICES=0</code> to run on GPU no. 0.</p>
  
  <p>How can I pick between the CPUs instead?</p>
  
  <p>I am not intersted in rewritting my code with <code>with tf.device("/cpu:0"):</code></p>