Hi all,
This is for Nvidia graphic card users only who have the latest drivers installed....
I have installed NvidiaInspector and used the FSX settings as shown here - http://forum.avsim.net/topic/324786-nvidia-configuration-guide-inspector-2xxxx-drivers-version-20-explanations-of-all-settings/
Then turned anti alliasing off in sse. My frame rates improved by 5-10 fps (depending on area).
Hope this helps.
Gordon