Tensorflow Slower on Python 3 vs. Python 2
When operating Tensorflow from python most code to feed the computational engine with data resides in python domain. There are known differences between python 2/3 when it comes to performance on various tasks. Therefore, I'd guess that the python code you use to feed the net (or TF python layer, which is quite thick) makes heavy use of python features that are (by design) a bit slower in python 3.
My tests show that Tensorflow GPU operations are ~6% slower on Python 3 compared to Python 2. Does anyone have any insight on this?
Platform:

Ubuntu 16.04.2 LTS
Virtualenv 15.0.1
Python 2.7.12
Python 3.6.1
TensorFlow 1.1
CUDA Toolkit 8.0.44
CUDNN 5.1
GPU: GTX 980Ti
CPU: i7 4 GHz
RAM: 32 GB