iWarp (aka RDMA support, TCP offload and kernel bypass on Ethernet) will be for some a viable alternative to Infiniband as a cluster link, especially on the new 10 GbE adapters. Microsoft's MPI will make use of it, as long as a Winsock direct provider is supplied by the manufacturer.

For the o/s to take advantage of iWarp, there are a few steps to be taken.

- Install 2003 SP2 or SP1 + scalable networking pack

- Make sure that NETDMA support is enabled by the driver (card advanced properties) and  WSD providers are installed. Refer to your adapter documentation for the correct installation and configuration procedure.

- Disable tcp chimney offload.

- Disable firewall, NAT or IPSec on the interface.

- See http://support.microsoft.com/?kbid=912222 for more information.