A data storage system has a circuit board module, a set of Serial ATA
devices, and a set of Serial ATA cables connecting the circuit board
module to the set of Serial ATA devices. The circuit board module
includes a circuit board, multiple host circuits mounted to the circuit
board and multiplexer circuitry mounted to the circuit board. Each host
circuit is configured to perform data storage operations on the behalf of
an external client. The multiplexer circuitry is configured to (i)
receive control signals from the host circuits and (ii) provide
communications pathways between the host circuits and the set of Serial
ATA devices in response to the control signals. Such an embodiment
alleviates the need for multiple versions of disk drive assemblies and
their associated costs.