The Storport driver supports an I/O model tailored specifically for high-performance buses. This I/O model allows miniport drivers to operate in full-duplex mode, which means that a miniport driver can add new requests to its queue even while it is in the process of completing others. Moreover, in full-duplex mode, the miniport driver does not have to synchronize the execution of its StartIo and interrupt service routines. This can lead to significant performance enhancements. However, miniport drivers must be designed to take advantage of full-duplex mode, because Storport operates in half-duplex mode by default.
A miniport driver must configure Storport to operate in full-duplex mode while executing its HwStorFindAdapter routine. It does this by initializing the SynchronizationModel member of the miniport driver's PORT_CONFIGURATION_INFORMATION (STORPORT) structure to StorSynchronizeFullDuplex.