If you search around there are a bunch of things you can do to bump performance. It doesn't sound like you are getting optimal performance.

FWIW I'm running an i5 , 16gigs ram, and a 940mx, and I get better performance. (usually 17-22 with max draw distance, but it does dip under heavy load) (also none of the optimizations I have found dramatically changed this)

* Edit : video card has 2 gigs ram , i think this is a bottleneck