dynamics and paint effects (dynamics especially) will run quite slowly on anything other than a top line comp. You may want to turn on caching for your dynamics stuff as soon as you are happy with it that way your comp will not run the simulation each time.
I have a p3 700 with 256megs ram and it runs ok, but my motherboard is old and my graphics card is crappy to the extreme but it's usable.
Technical Director - Framestore
Currently working on: Your Highness
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