Hi.  I run both FS9 and FSX on the same computer, am changing from duel core processor to quad core, Windows 7, the machine is high spec. and should run FSX pretty well, but getting concerned on reading in forums the disappointment in frame rates running quad core for FS9. I would be interested in any views or experiences with the latter. I thank you in advance for any comments.     Dobermann

FS9 cannot utilise quad cores, which is reasonable since they weren't around at the time.
You can set the "affinity" to use 2 cores on a dual core machines, but I've not seen any particular improvement with this.
Any decent modern computer can run FS9 with one hand tied behind its back, which for me is part of the attraction.
I just set everything to max, and throw the most complex scenery and AI traffic at it, and watch the show.

Do not set your hopes too high for FSX however, I have run it on a bleeding-edge machine and ended up just flying a single-engine with no AI somewhere in the mountains, before I felt any satisfaction. This is not meant to be FSX-bashing, just my experience. Apparently some others find satisfaction more easily.

In theory if you have a zillion other apps running on your computer under Win7 say, multicores would handle other stuff and not impinge on FS9.
This might create the illusion of improved FS9 performance.

(although I did need to allocate more RAM to the game).

Mmmm...how did you do that?  Sounds an interesting option...