Why tf tries to occupy so much GPU memory for simple test?

[vedrusss]

Hi there,
I'm trying to run your light_head_simple_demo.py with provided model model.ckpt-121397
But while starting the script I run into out of memory issue: while restoring parameters from the checkpoint tf tries to occupy > 14Gb of GPU and falls because I have less than 16Gb.
But the model weight file has size less than 0,5Gb.
Does it really require >16Gb? Or I have somewhere wrong settings for the model? How much memory does it requires for that test?

For test I use tensorflow docker container with pre-installed Ubuntu16, cuda9.0, tensorflow1.6, python 3.5

Thanks