I've enabled GPU rendering (CUDA) for my GTX 1060 and it's awesome. 3D viewport views render much faster than before. Monitoring my GPU shows it at 60-100% usage while Cycles samples.
However, when rendering still images or animations to file, my GPU usage is flat or at zero as CPU usage spikes.
I'm running blender 2.79b on a win 10 system with one GPU.
Yes, I have the latest driver from Nvdia. (399.07)
Yes, I have gone to the Nvdia control panel and set the OpenGL rendering GPU to my card.
*Update. I seem to have located a bottleneck in GPU usage. Looking at MS Process Explorer, it seems that blender is only using, or only has use for part of the GPU..? I'm uncertain if the types of scenes I create is a factor in creating this bottleneck, or if the problem is a solvable blender config issue.