"Curiouser and curiouser, said Alice" ... OK, I'm running a nice big iMac 24" desktop with a 2.8 GHz processor, 2 Gb of RAM and 4 Mb cache. The graphics card has just 256 Mb of RAM, which is the area I would expect to have possible problems [my Alienware had liquid-cooled Quad graphics cards
].
Anyway, I have absolutely
zero trouble running TSM, whereas TS3 really gets bogged down sometimes.
One thing I always do before playing
either of them is quit any running programmes and clear browser history. And of course ensure that all software is up to date, but then Apple does that automatically for all applications, printer drivers etc.