Hello, New to sim racing and downloaded GSC2013 today. I am having serious lag issue (unplayable). I am not sure what the problem is. I am able to run iRacing at 80-120 FPS with medium detail on. I am running an AMD FirePro V4900 grahics card with dual AMD A4-5300 proc. Any ideas? I have left the default video popup setting when the game installs. Does this need to be modified or does GSC auto configure for best available settings? Thanks.