Windows HPC Server 2008 introduces a new low-latency RDMA network API known as "Network Direct".   This RDMA interface in addition to and distinct from the existing "Winsock Direct" interface.   The Network Direct interface introduces several advantages over Winsock Direct including no dependency on the Winsock stack and much lower latency metrics.  MS MPI is being developed to take advantage of this new interface. 

This means that Infiniband vendors, for instance, will need to provide HCA Network Direct providers in addition to (or perhaps instead of) the Winsock Direct providers published previously.  Consequently, development is underway by both Microsoft and partners to enable full support for the entire network stack. 

For programmers, the Network Direct API provides a model similar to the User Mode Driver Framework (UMDF).  MS MPI will be the first user-mode application to leverage Network Direct. 

Windows Server 2008 Open Fabrics Infiniband drivers are published as follows: 

Location of the bits and doc:

· Kernel component for Network Direct will be placed on the Open Fabrics branch:

http://openib.tc.cornell.edu/downloads/binaries/

The Windows HPC Server 2008 beta1 "HPC PACK SDK" includes relevant documentation.  The SDK is available on http://Connect.Microsoft.Com (search for Windows HPC Server 2008).