Graphic problem with my MacBook pro retina when gaming

I am playing Left 4 dead 2 in early December with 2880x1800 with very smooth graphics. But then now it is very laggy when operating at 2880 or even 1920, I need to switch to 860 to have a very smooth graphics. It is very laggy even when it is using GT650M. I am not sure if it is the OSX problem or the hardware problem. It is very laggy now even playing Team Fortress 2. Can anyone answer me and help?