I have the same issue with a GTX1080 card on 388.31 drivers. I get heavy lag in the editor, with framerate dropping from around 100 to about 5 FPS. It works occasionally but then starts lagging again after a while.
It mostly happens when I have one or more windows on my second monitor, for example the Content Browser. If I minimize the Content Browser, or dock in in my main window it stops lagging.