Various techniques are provided for selectively allocating a buffer adapted to be shared for storage media device data communications and downstream device data communications routed through a hub. For example, in one embodiment, a method includes detecting if one or more downstream devices are connected to one or more downstream device ports of the hub. The method also includes, if any downstream devices are detected: allocating a first portion of the buffer for a storage media device controller, allocating one or more second portions of the buffer for the detected downstream devices, wherein each of the second portions is associated with a corresponding one of the detected downstream devices, and passing the storage media device data communications between a host device and the storage media device controller through the first portion of the buffer and not the second portions of the buffer.