My PC can deal with ARMA, i have a i7 4770 processor and a GTX 780 graphics card, I can run the game in ultra very smoothly, I never had issues in the main menu before (before ZEUS upde.)
I you wish to see the issue your self, I uploaded a video here: https://www.youtube.com/watch?v=8YuSDHNGojU
p.d. I also tried the DEV version, works way better there, tho I still get a loading from the main menu to the MP menu, ehich I don't recall ever having that loading before. But on DEV I can't join 90% of the servers.