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?
MacBook Pro with Retina display, OS X Mountain Lion (10.8.2)