I cn remember Flanker 2.0 and 2.5, the game limited the FPS to 30. Nothing beyond 30 is needed, so the game save resources doing it.
Set you particles at maz, and watch a battleship exploding, if your FPS dont droops under 30 you are sure you can play the game fine.
To improve the FPS you may do some things.
Unistall game, defrag disk, install game over a fresh defrged disk.
Reduce AA and AF into drivers control panel. Set them to "best performance" instead "quality"
Close all non wanted programs loaded at INI, use the msconfig.exe for it.
Run the game closing all background programs, use End It All 2.
Have not unnecesary task running into the background, use Security Task Manager.
Close all antivirus, antispyware, or similar security programs when runs the game, BE SURE YOU ARE NOT CONNECTED TO INTERNET TO DO IT.
Run some memory control program... like in example Hare or similar.
And too much important :
DO NOT USE an onboard sound card, buy a PCI one with Hardware Acceleration, if posible, with its own built in memory, onboard sound cards "EATS" your resources.
May be this can help you ....