I don't know if this will be of any use to you, but have just found it.
Start FS in windowed mode.
Press CTRL+ALT+DEL to get the task manager, click performance tab, and observe that FS is only using one processor.
The left graph will show a heavy load, the right a light load.
Click on processes, and look for FS9.exe, and select Infinity. Remove the check mark from one processor.
Close the window and then repeat the process, and select both processors again.
FS9 will now spread the load over the 2 processors.
Or search the Microsoft Support for Dual core hot fix.
ie textures not loading fast enough Check your visibility settings in the registered version of FSUIPC.
Hope this will be of help, or you already know this.