I keep play SMAX till now, and it works fine on my Win7/x64.
- Make a clean installation SMAX (or backup an existing copy);
- Install SMAX patch, searchable
smacp4e, last time seen here;
- Install Windows Fix, searchable
smacxp103fus or SMAC Win2000 XP Compatibility Update v1.03f; last time seen here.
As far as I know, all patches are available for SMAC and SMAX.
Then try the following settings in config:
DirectDraw=0 ;; important
Video Mode=2560 ;; your screen resolution
ForceOldVoxelAlgorithm=1 ;; important
The patches above have quite a few of bugs fixed, including operation on fast or non-Intel CPU's, crashes on air-to-air combat (when fighter defend the city against bombers), division by zero when automated units in polar areas, and many others.
It even works like a charm on WQXGA (2560×1600) screen with no crashes on scrolling.
And it does not require any compatibility settings in Windows.