ArmA 3 optimization help

hi everyone,

my pc can run arma 3 on standard, with 30 fps, but i have frame drops to 5-10 fps.
are there things i can do for a better optimization, and get more frames?

 

I've got a AMD Athlon II X4 750K, with a cheap mobo

4Gb of ram

and a Nvidia 750 TI (MSI Twinfrozr)

 

i will be adding a upgrade to this pc soon, so if you got some advice for it is always welcome :D