Verifying if GPU is actually used in Keras/Tensorflow, not just verified as present

Question

I\'ve just built a deep learning rig (AMD 12 core threadripper; GeForce RTX 2080 ti; 64Gb RAM). I originally wanted to install CUDnn and CUDA on Ubuntu 19.0, but the install

Answer 1

Another way to analyse the performance of the GPU which I ended up finding (for Windows users) was to go to the "Task Manager" and change one of the Monitors in the "Performance" tab to CUDA, then simply run the script and watch it spike.

Also adding this

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

before the keras import to toggle between CPU and GPU also shows a remarkable difference (although for my simple network, the quicker CPU can be explained here).