Dear Derek, Because of the adaptive mesh evolution, the dimension of the final matrix is ~360,000*360,000 (sparse matrix). However, I am wondering why the cost time of the parallel_sort() increases very quickly. Thanks.
Regards, Yujie On Thu, Feb 11, 2010 at 4:07 PM, Derek Gaston <[email protected]> wrote: > How large is your problem?? If libMesh is dominating your solve time... > then you're problem probably isn't large enough to be distributed over so > many processors. > > Derek > > On Feb 11, 2010, at 2:53 PM, Yujie wrote: > > > Hi, Libmesh Developers, > > > > When I run the codes in parallel mode, I found the performance is not > always > > improved with the increase of the CPU number. I tried to find the > bottleneck > > using the libmesh performance table. I found the problem is from Mesh > > Communication::parallel_sort(). > > At the beginning (from 2 to 14 CPUs), the cost time of Mesh Communication > > takes a small percentage of the total time (Check the following table). > > However, when the CPU number changes larger than 14, the performance of > Mesh > > Communication becomes worse, especially parallel_sort(). I don't know > > whether it is normal. Could you give me some advice? Thanks a lot. > > > > Although there are 8 CPUs in one node of the cluster, each CPU added is > > from different nodes compared with previous one by using "-machinefile " > in > > MPI when I add the CPU. > > > > CPUs Mesh Communication > > 1 > > 0 2 > > 2.6 3 > > 2.6 4 > > 2.7 5 > > 2.7 6 > > 2.7 8 > > 2.9 10 > > 2.6 12 > > 3.4 14 > > 4.2 16 > > 7.2 18 > > 7.2 20 > > 8.7 22 > > 9.5 24 > > 13.8 26 > > 15.3 28 > > 19.4 30 > > 24.2 32 > > 34.6 34 > > 32.4 36 > > 36.6 38 > > 39.1 40 > > 46.9 > > Regards, > > Yujie > > > ------------------------------------------------------------------------------ > > SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, > > Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW > > http://p.sf.net/sfu/solaris-dev2dev > > _______________________________________________ > > Libmesh-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/libmesh-users > > ------------------------------------------------------------------------------ SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
