OK, after playing some more, it seems like setting the affinity only helps. It doesn't eliinate the problem. I'm still getting slowdown around cities. Unrelated, I'm also getting slowdown on this thread! It's weird, whenever I come back to this, the page hitches up. Weird.
You guys should sticky this, I bet alot of people will come into the forums asking for just such a tutorial.
Hey guys. I had this same problem, but seem to have fixed it. Try this, If you have a multi-core processor, switch the game's affinity to just one of your processors. To do this, hit Ctr-Alt-Del while the game is running, then right click "Elemental" under Processes. Down the bottom of the list, see "Set Affinity". Just uncheck one. I hope this works for you like it did for me!
Oops wrong thread.