title: Tensorflow not detecting GPU - Adding visible gpu devices: 0
body: <p>I have a system with an NVIDIA GeForce GTX 980 Ti.  I installed tensorflow, and look for the gpu device with tf.test.gpu_device_name().  It looks like it finds the gpu, but then says "Adding visible gpu devices: 0"</p>
  
  <pre><code>&gt;&gt;&gt; import tensorflow as tf
  &gt;&gt;&gt; tf.test.gpu_device_name()
  2019-01-08 10:01:12.589000: I tensorflow/core/platform/cpu_feature_guard.cc:141]
   Your CPU supports instructions that this TensorFlow binary was not compiled to
  use: AVX2
  2019-01-08 10:01:12.855000: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1
  432] Found device 0 with properties:
  name: GeForce GTX 980 Ti major: 5 minor: 2 memoryClockRate(GHz): 1.228
  pciBusID: 0000:01:00.0
  totalMemory: 6.00GiB freeMemory: 5.67GiB
  2019-01-08 10:01:12.862000: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1
  511] Adding visible gpu devices: 0
  </code></pre>