Also, I'm not sure how new you are to Arma, but what are you counting as "low FPS"?
Arma metrics differ from other games in quite a noticeable and meaningful way. I think I can easily speak for most (if not all) of the unit when I say that I've never seen Arma frames anywhere close to (for example) CSGO frames.
I regularly play Arma with a 300+ ping and <30 FPS and it's never been a major problem.
That being said
It's important to understand that in Arma, the quality you have any given item set to means more than just it's quality. For example, if you have Shadows set to Low, they will be CPU rendered. If you set them to High, they will be GPU rendered. This means that if your GPU is better than your CPU (as is my case), you may actually get higher performance on higher quality settings.