Service Pack 4 has replaced the lame Full Duplex support in Windows NT 4.0, with a new feature that deserializes communications between NDIS and the your NIC's miniport driver.
If your NIC is capable of running in deserialized mode on a SMP (Symmetric MultiProcessor), you will observe significant performance improvements.
NOTE: Old style Full Duplex is still supported for NICs that do not support full deserialized operations.
NOTE: Full Duplex refers to the ability of your NICs minport driver to simultaneously send and receive to
Windows NT on an SMP computer AND to the MAC layer allowing simultaneous reception and transmission of data
by your NIC. If you have a modern NIC on an
SMP computer running Windows NT 4.0, SP4 (or greater), both functions are now supported.
