A smart storage device is provided. The smart storage device includes a smart interface connected to a host device. An accelerator circuit is connected to the smart interface through a data bus conforming to a CXL.cache protocol and a CXL.mem protocol. The accelerator circuit is configured to perform acceleration computation in response to a computation command of the host device. A storage controller is connected to the smart interface through a data bus conforming to a CXL.io protocol. The storage controller is configured to control a data access operation for a storage device in response to a data access command of the host device. The accelerator circuit is directly accessible to the storage device through an internal bus connected directly to the storage controller.