With Poser 8 you don't need more memory, it's not 64 bit so it will never use more than 4 GB. More RAM isn't likely to help you.

Also, among the things which are too slowly you did not mention rendring but saving the figure, loading stuff, conform a figure. When I had Poser 8 it did not feel slow, and my system then was a dual core with 4 GB RAM IIRC. 

Windows 7 has a defrag task running regulary per default, IIRC.

Is your hard disk old or very full? Did you change the number of undo levels?

I'm just guessing at the moment. 

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

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