I just did, at least the ping pong, the results are slightly worst and presents the same drop at 64KSee attachment.
a comment: to run with the btl mx i need to use --mca btl mx,sm,self -mca mtl ^mx or i get a mx_open_endpoint failure due to myrinet busy (I have already increase the number of endpoints to 16 ) On Wed, May 6, 2009 at 7:31 PM, Scott Atchley <atch...@myri.com> wrote: > On May 4, 2009, at 10:54 AM, Ricardo Fernández-Perea wrote: > > I finally have opportunity to run the imb-3.2 benchmark over myrinet I am >> running in a cluster of 16 node Xservers connected with myrinet 15 of them >> are 8core ones and the last one is a 4 cores one. Having a limit of 124 >> process >> >> I have run the test with the bynode option so from the 2 to the 16 process >> test is always running 1 process by node. >> >> the following test pingpong, pingping, sendrecv, exchange presents a >> strong drop in performance with the 64k packet size. >> >> any idea where I should look for the cause. >> >> Ricardo >> > > Hi Ricardo, > > I believe that the pingpong results show the drop that you are > experiencing. There is a drop at 64 KB and 128 KB and it returns to the same > level at 128 KB. > > What you are seeing in the pingpong results is the change over from eager > to rendezvous within MX. Up to 32 KB, we use an eager protocol (send the > data even if there is not a posted receive). After 32 KB, we switch to a > rendezvous protocol. > > I do not believe that this limit can be changed. Have you tried the same > application when using the MX BTL? > > > Scott > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
IMB1-PingPong-BTL.results
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