Your cat won't automatically know his name unless you train him. There's even less desire on his part to come when called unless you give him a reason.
Took about a month for my cats to know their names, then come when called. It took some time of consistent training and rewards to get there. Whenever I petted them, I'd say their name to them; I'd look at them and say their name; at mealtimes I'd call their names, etc. I had treats all over the house, and at different times, I'd just call one of them, and when kitty came, I'd give a treat to him/her.