How to run Tensorflow on CPU

Question

I have installed the GPU version of tensorflow on an Ubuntu 14.04.

I am on a GPU server where tensorflow can access the available GPUs.

I want to run tensorflow on the CPUs.

Normally I can use env CUDA_VISIBLE_DEVICES=0 to run on GPU no. 0.

How can I pick between the CPUs instead?

I am not intersted in rewritting my code with with tf.device("/cpu:0"):

Answer 1

You can also set the environment variable to

CUDA_VISIBLE_DEVICES=""

without having to modify the source code.

Answer 2

If the above answers don't work, try:

os.environ['CUDA_VISIBLE_DEVICES'] = '-1'