On Wed, 2006-05-10 at 08:36 -0700, Vu Pham wrote: > Roland Dreier wrote: > > BTW, does Mellanox (or anyone else) have any numbers showing that > > using FMRs makes any difference in performance on a semi-realistic > > benchmark? > > > > I'm using xdd to test the performance > www.ioperformance.com/products.htm > > The target is Mellanox srp target reference implemenation > with 14 SATA spindles > > I can get ~780 MB/s max without FMRs and ~920 MB/s with FMRs > (using 256 KB sequential read direct IO request)
Wow, that's awesome Vu! So what's the consensus on the reason for the improvement? - Fewer WR to send the same amount of data because the memory is virtually contiguous? - Fewer PDU due to larger writes and better packing? - Something else? Are these huge reads, ... or even better ... what are the parameters to xdd? Did you quantify the FMR registration cost per MB of registered memory space? This would be a very good number to have for figuring out where the sweet spot is... Thanks, Tom T. > > Vu > _______________________________________________ > openib-general mailing list > openib-general@openib.org > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
