A method of operating a storage device including first and second memory regions includes adjusting a write ratio of the first memory region to the second memory region for write data received from a host in response to a write request from the host, and writing the write data to the first and second memory regions at the adjusted write ratio. The first memory region includes memory cells having a first write speed, and the second memory region includes memory cells having a second write speed that is different from the first write speed.