iMac/Knights of the Old Republic game install/running problems. Please Help.

[Chrishouse6409]

I have a 2 year old iMac with 173.72 GB available purchased from Best Buy. It's running Mac OS X Version 10.5.8 with a Processor of 2.4 GHz Intel Core 2 Duo. I have just received a purchase for a used copy of Star Wars Knights of the Old Republic w/game manual for the Mac from ebay. The bottom of the disc has a lot of wear, but showed that it installed on my iMac. I downloaded and installed the 2 patches available for the game from Macgamefiles.com. I started up the game and a message pops up saying that I need a faster processor that's 500 MHz or faster for no interruption during game play. I clicked "okay" on the message and the game tried loading, then went back to my desktop with another message saying, "The application Knights of the Old Republic quit unexpectedly." I then clicked on "report to apple" and tried restarting the game again and the same thing happens over again. I have no idea what the problem is or what I need to do to fix/improve these issues. I'm a bit frustrated with it. I just want to play this game and have it done by the time the MMO Star Wars The Old Republic comes out for PC. Sorry if I'm too thorough with the info on my iMac. I just wanted to be clear to help those of you who may be able to give me an accurate diagnosis. Your help is greatly appreciated.