I have an A717-72G which has similar hardware.  I play a few low-spec games on it.  There are some known issues with running the default power saving mode of "optimum" in the nVidia control panel with some games.  What I do is set my global power setting to optimum then for each game on the Programs Settings tab of nVidia control panel I set the power saving mode to adaptive. 

There is some benefit in putting the nVidia global power setting on optimum.  I found it makes a noticeable difference in power consumption when running desktop stuff on battery.  Adaptive won't allow the nVidia GPU to shut down completely when it's idle.

I also set the preferred GPU for each game.  On my particular laptop low-spec games don't always auto-detect in favor of the nVidia GPU.  

Don't know if this stuff will specifically address your issues, maybe some help.