A memory module operable to communicate data with a memory controller via a memory bus. The memory module comprises memory devices and logic configurable to receive and register a set of input address and control signals associated with a read or write memory command and to output data transfer control signals. The memory module further comprises circuitry coupled between the memory bus and the memory devices. The circuitry is configurable to be in any of a plurality of states including a first state and a second state, and to transition from the first state to the second state in response to the data transfer control signals. The circuitry in the first state is configured to disable signal communication through the circuitry. The circuitry in the second state is configured to transfer the data signals associated with the read or write command in accordance with a transfer time budget of the memory module.