Testing if tensorflow is using GPU acceleration

tf-test.py

import tensorflow as tf

# If this program does not throw any error while running, it means GPU acceleration is being used.
# If there is an error message after running this program, you need to check you graphics driver settings

with tf.device('/gpu:0'):
    a = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[2, 3], name='a')
    b = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[3, 2], name='b')
    c = tf.matmul(a, b)

with tf.Session() as sess:
    print (sess.run(c))