A solid-state storage subsystem, such as a non-volatile memory card or drive, includes multiple interfaces and a memory area storing information used by a data arbiter to prioritize data commands received through the interfaces. As one example, the information may store a priority ranking of multiple host systems that are connected to the solid-state storage subsystem, such that the data arbiter may process concurrently received data transfer commands serially according to their priority ranking. A host software component may be configured to store and modify the priority control information in solid-state storage subsystem's memory area.