When I play Modern Warfare 2 using anti-aliasing on my Macbook Pro and no monitor, the game lags too much to play.
But lo and behold: When I plug in a monitor to my Macbook Pro and turn on AA and put all textures to high, the game runs just fine.
Why is this? why does plugging in a monitor improve performance?
Without the monitor, I can run the game at medium resolution, but no VSync and no AA (but medium specular)
With the monitor, I can run the game at highest resolution, no VSync, 2x AA and medium specular unless there is lag.