A data deduplication method is executed by a controller for a solid state drive (SSD). The controller receives a signature for a block of data. The controller performs a comparison of the signature and information in a signature library and determines whether or not the signature matches the information. The controller sends a signal that indicates a result of the comparison. If the signature and the information match then the signal has a first value indicating that the block of data is already stored on the SSD; if the signature and the information do not match then the signal has a second value that is different than the first value.