I remember the first time I was playing me and a mate accidentally sneaked up on two snipers just laying down in some huge field and we blasted their shit, I then realized we couldn't pick up the ghillie suit, but we got a AKM and a FAL :3
Not sure what it is but runs really well. This game didn't work on my laptop so I bought a new work station tower and it's running really well. I recommend anyone to get GameBooster if you are getting low FPS.