[Younggun]

Try this

viewtopic.php?t=3127&highlight=advanced+tweaks+il2+stutter+fps+problems

And if you have a multicore PC you need to change this;(in your config. file in your root folder)
[rts]
;ProcessAffinityMask=1
To
[rts]
ProcessAffinityMask=2

Since IL2 was not designed to run on multicore processors.

Good Luck!