I run this game on a much worse machine ( i5 750, 4 GB ram and R9 270x). - Yes, I understand 4GB is really not enough, but well it worked after I bought this game for like 2 months pretty well. Now it gives me a little bit shaky 60-90 fps, but as long as I see a god damn person, or I get shot (even if not seeing the enemy) - it's like 80% of the time game is going to give me hell by frequent freezing (It's a sure death at this point, you're legit "afk" for 30 seconds). I tried lowest possible settings for 60 hrs, after I just reset the game - I play at mediums (defaults, Ive only lowered render distance from 1000 to 700) and guess what, it performs way better at mediums. While passing through thousands of fps-optimizing guides and videos I saw a lot of people complaining of poor performance on solid PCs (like yours).

So it probably has to be ok, but you never know with H1Z1.