The NDIS 6.20 interface introduces support for more than 64 processors. Previous NDIS versions are limited to no more than 64 processors (32 in x86 versions of the operating system).
To remain backward compatible with older implementations, NDIS supports processor groups. Software that has not been updated to support more than 64 processors can default to processor group zero.
To support more than 64 processors, NDIS 6.20 and later provide updated versions of these interfaces:
Processor information device driver interfaces (see NDIS System Information Functions)
Resource allocation (see NDIS Memory Management Interface)
Read and write locks (see NDIS Read Write Lock Reference)
Some of the NDIS device driver interface elements are obsolete for NDIS 6.20 and later drivers. For more information about obsolete interfaces, see Obsolete Interfaces in NDIS 6.20.