Optimal Memory for 4 gig imac

There are two places to set memory: preferences/memory and in the "edit the virtual machine" window before windows boots. The odd thing is that the amounts are different and seem to require this. For instance, I set the amount to 1000 megs in preferences and 1000 by clicking on the memory link, but parallels required me to set this to 900.

Regardless, the parallels suggests 500 megs: would it ever suggest something different and what might the optimal level be? Finally, once the optimal amount is chosen, how should this be set, given the contradictory way the two memory level is set in two places.

thanks

 

Hey Parallels,

This is odd that not a single parallels person answered this post. Please pay attention to your customer base - don't be quark...

thanks,
Jim