The game normally runs very smoothly on my system, even at 1280x1024, with Very High image quality and 4x Anti-Aliasing and Anisotropic Filtering. There is the occasionally hiccup when first viewing a city, but other than that it is very smooth to scroll and to play.
However, every time I view any section of the 3D travel map where Fog of War is present, the frame rate decreases dramatically. By Fog of War I mean the black haze that obscures parts of the map that I have not yet traveled to. Once I explore and push back the Fog of War the slowdown stops, but if there is even a tiny bit of it on the screen my frame rate drops to a stutter. This happens at all resolutions, texture qualities, and AA/Anis settings.
Is this a known issue? Does anyone else experience this?
Windows XP SP2
Athlon 64 3000+
1024 MB RAM
NVidia GeForce 7900GT 256 MB
Forceware 84.25 drivers
Sound Blaster Live! 24-bit