When I first installed the new updates and began to play DayZ through steam, I had terrible fps for no clear reason. Earlier today, I found out a way to get this fps up from about 13 to 30-40. After you install the beta patch, instead of using the parameters: "-beta=Expansion\beta;Expansion\beta\Expansion" to run the patch in steam, use these parameters: "-mod=Expansion\beta;Expansion\beta\Expansion". Be sure to post whether or not it worked for you.