I *believe* that this value came out of IB hardware history. I.e., when we wrote the openib BTL, some empirical testing showed that 12k was a good value.
On May 7, 2012, at 9:25 AM, Simone Pellegrini wrote: > Hello, > I have one of those 1M dollar questions I guess, but why the eager limit > threshold for Infiniband is set to 12KB by default in OpenMPI? I would like > to know where this value comes from. I am not wondering whether this is a > good setting for this parameter, but just why this is considered to be a good > trade-off for all Infiniband clusters. What I would like to know at the end > of the story is whether this is an empirical value or if there are > architecture characteristics of IB which make this value come out of pen and > paper work (any pointer would be appreciated). > > thanks in advance for the reply. > > regards, > Simone P. > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
