A semiconductor package includes: a memory sub-package including a first connecting layer and a plurality of memory chips disposed on the first connecting layer; a logic sub-package including a second connecting layer, a controller chip disposed on the second connecting layer, and a buffer chip connected to the controller chip and the plurality of memory chips; and a plurality of inter-package connecting members each of which connects the memory sub-package and the logic sub-package, wherein the buffer chip is connected to the plurality of memory chips via a plurality of first data transfer lines each having a first data transfer rate, the buffer chip is connected to the controller chip via a plurality of second data transfer lines each having a second data transfer rate, and the first data transfer rate is less than the second data transfer rate.