Since I have a 64-bit machine, but only 2 gigs of actual RAM, I decided to see how long my system could support a game on immense (5 AI opponents). It turned out to be about 3 hours of actual play before the game itself crashed.
The fun part was how my machine kept trying to reboot itself over and over until I removed one stick of RAM. Now it seems to work fine, but I had no idea the game could overheat things enough to damage anything.
I did e-mail the smartexception file to Stardock.