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Just an example for you- I used to RUn WoW on my G5 with 8mg Ram with the ATI card using my Apple 30" display. I switched to a Mac Mini with the 9400m and 4mg Ram. Frame rates are now vastly improved, it's quieter, it uses less electricity and the loading times are much much quicker.

I would say you are right in that the two cards perform similarly, but all the other advantages the mac mini brings will improve your gaming experience.

Hope this helps you. (G5 for sale if anyone wants it :))
 
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