Well I've seen quite a few threads with people having problem with P7 and crappy performances. I used to have some problems (well the major one was the freakin speed!!). I was doing some reading on the old paging file and how it is involved in the process calculation and came to a weird conclusion...
I took an old crap PC, I think it's pentium III, 256 Mb of RAM, installed XP 2 then installed P7.
You must think I'm nuts, but well after a day also I managed to get out a simple render. Then I went into the virtual memory management part of XP and changed the settings as follow:
Only set your paging file on the C drive (or what ever your primary drive letter is). Set the minimum size to 1024Mb and the maximum to 1060Mb. Click SET. If you have then another drive and a paging file set up on it, remove it.
Then I restarted, et voila!!
Absolutely flying!!
I did a render with satin materials on dynamic clothing, Kozaburo hair and two mirrors behind the character... Less than an hour to build scene and render.
Try it and see if it can help...
My new email address: Frederic_lievre@vodafone.ie

No real reason to set the Min-max swap to different sizes, given the amount of RAM.
Oh, try it with Win2k Pro on the same system, it MIGHT just be a little bit faster...