Intel MPI OFA Experience Sean Hefty (don’t shoot the messenger)

2 Performance  OFA uDAPL is the best fit for Intel MPI  uDAPL within 10% of native verbs  Mellanox: 2.8 vs. 2.6 usecs  Qlogic: 4.5 vs 4.1 usecs  The results are NetPipe uDAPL vs. verbs

3 Usability  uDAPL compatibility required between Linux and Windows  Calling conventions must match  Interoperability testing needed  Need to know Endianess and size of keys  uDAPL requires IPoIB  Can we do without?

4 Usability  Improve connection scaling  Longer timeouts  Faster connection setup  Want fewer user controls settable only by root  Is there a way to speed up distros adoption rate?

5 uDAPL  uDAPL provider behavior differs from vendor to vendor  Intel MPI needs special treatment for each provider  Different interpretations of the DAT standard  iWarp: active side of connection must send the data first  Want support for uDAPL 2.0 spec with 1.x compatible library