@ jono thanks ill try that
i think the increase in performance is mostly due to faster copying of the boards and faster move generation which allows greater search depth
currently i have to manually copy all the values in one board representation into a new 2d array cause the .clone() method does not clone the array in the board representation
sry if it wasnt clear by 8x8 i was referring to a 2d-int array with length 8
thats what im currently using although black is -1 cause its easier to get the enemy color.