Laggy Simcity 4 on Tiger


I recently bought and installed a copy of Simcity 4 on my 1.42Ghz (256mb) Mac mini but found it unbearably laggy. Is there any way to remedy it, perhaps?
Well, the problem is that SimCity 4 is unbearably laggy on a lot of systems (part of the problem is the heavy lifting it expects from the video card, another part is that the port just isn't very good). There are some patches, but if it doesn't improve noticably with more RAM (I play UT2k4 just fine on a 1.25 Ghz Mini with 512MB of RAM), then it is the game.