poor draft analysis in creo 3 m020

I have a plastic model that performs a complete model draft analysis in under 1 second in wf3.0 (250mb ram) , 5 seconds in creo2 (250 mb ram) and I end task after 2 minutes and over 5.5 gb ram in creo 3 m020. This makes us wonder if new is not often better. any thoughts PTC????