Thanks Indeed I can turn down some options (I set visibility to 5 miles max ) and the I am pretty sure that with a lower resolution ( running now 1600 x 900 if I remember well) I will run the a/c without any problem. However, 80 fps, been the lowest frame rated displayed during the almost freezing intervals (around 5 to 15 seconds in duration) , should not produce this kind of behaviour. Maybe more Ram can help. BTW, I have a 1GB ATI Radeon Many Thanks