If there were one "best" setting for each of these items, then we wouldn't have made them preferences. These are preference settings because some people like them one way, and some another; or because they work better one way in one circumstance and better another way in another circumstance.
See this page for links to descriptions of what each preference does and/or what context it's useful in.
See this FAQ entry for information about memory & multiprocessing settings.
This page has more information about performance settings.
Thanks for replying. My main concern is for the 3 preferences that are in bold. I was hoping that you (or someone) could suggest the best
settings for these three preferences based upon my PC specs.
If this machine was yours, how would you tweak these three preferences?
If you follow the links that I provided, you'll find a lot of information about recommendations for performance settings.