If I use my integrated gpu (Intel HD Graphics 4600)
There are large fps dips in both full screen and window mode (unless I downgrade my resolution).
If I use my dedicated gpu (GeForce GTX880M)
There are only large fps dips in Full screen mode (lowering the resolution stops the dips).
Window mode runs at 60 fps at all times on any resolution.
stretching the window size did not change the frame rate.