According to one embodiment, an electronic device includes a nonvolatile memory that includes blocks and a controller. The controller transmits information to the host. The information indicates a first logical address range corresponding to cold data stored in the nonvolatile memory, and a processing amount for turning a cold block that comprises the cold data into a block to which data is writable. The controller reads the cold data from the nonvolatile memory in accordance with a read command that is received from the host and designates the first logical address range, and transmits the read cold data to the host. The controller writes, to the nonvolatile memory, the cold data that is received with a write command designating the first logical address range from the host.