*off topic question*
Kael, as you seem to have some good understanding of the game's inner mechanics, do you have any clue why it occupies ~50% processor utilization, even if the player is not doing anything?
I am not talking about intra-turn, nor any unit movement or whatever.
Let's assume you have done all your stuff during your turn and you just haven't pressed RETURN yet. Still, the game occupies these 50%...
(3.6 GHz P4, 2 GB RAM, 2 SLI-6800 GS, RAID-0 stripe etc. etc. etc... should be fast enough for the game, and no, nothing is running in the background...)
I assume its the graphics engine doing redraws. Even during times where the engine isn't doing anything but waiting for input Civ4 is processor heavy. Unfortunatly Firaxis didnt release the source to the graphics engine (I think its 3rd party so they cant release it) or I would dig into it to see what can be done to improve it.