I'm not sure if this is considered as a bug, but when i start a world and mine some stone, the moment i picked the first cobblestone up minecraft freezes for a split second, it happens every game, i tried reducing the settings but nothing helped. Good news is that this happens only once per game, and it won't happen a second time in the same game/world. As you can see my fps has gone down to 0 in the attachment when i tried picking up a cobblestone.