A memory expander includes a memory device that stores a plurality of task data. A controller controls the memory device. The controller receives metadata and a management request from an external central processing unit (CPU) through a compute express link (CXL) interface and operates in a management mode in response to the management request. In the management mode, the controller receives a read request and a first address from an accelerator through the CXL interface and transmits one of the plurality of task data to the accelerator based on the metadata in response to the read request.