A multi-host power controller (MHPC) of a flash-memory-based storage device is disclosed. In one aspect, the MHPC receives power mode change requests from each of multiple input/output (I/O) clients. The MHPC extracts and stores a “vote,” or a requested power mode, from the power mode change requests, and then applies a voting logic to the stored votes to determine whether to transition the flash-memory-based storage device between power modes. If the flash-memory-based storage device is not currently operating in the power mode determined by the MHPC, the MHPC is configured to issue a power mode change command to the flash-memory-based storage device to transition to the determined power mode. In this manner, the MHPC is able to control the power mode of the flash-memory-based storage device while receiving direct power mode change requests from multiple I/O clients.