<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #330066"><div>Hi,<br></div><div><br data-mce-bogus="1"></div><div>I have compiled GetDP with MPI option under Linux Ubuntu 16.04 on a machine w/ 6x2 CPUs and 32 MB of RAM.</div><div>When running the magnet.pro file given in the GetDP demos folder, I was expecting to get faster results with MPI<br data-mce-bogus="1"></div><div>than w/o and was quite surprise by the comparison as shown by the following outputs :<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>1) MPI run:<br data-mce-bogus="1"></div><div>***********<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>mpirun -np 12 /home/quemener/local/OneLab_gq/GetDP/bin/getdp magnet -solve MagSta_phi -pos MagSta_phi<br>Info : Running '/home/quemener/local/OneLab_gq/GetDP/bin/getdp magnet -solve MagSta_phi -pos MagSta_phi' [GetDP 2.11.1, 12 nodes]<br>Info : Started (Wed Aug 9 09:20:20 2017, Wall = 0.277839s, CPU = 0.884s [0.04s,0.116s], Mem = 287.254Mb [23.4609Mb,27.6289Mb])<br>Info : Increasing process stack size (8192 kB < 16 MB)<br>Info : Loading problem definition 'magnet.pro'<br>Info : Loading problem definition 'magnet_data.pro'<br>Info : Loading problem definition '../templates/MaterialDatabase.pro'<br>Info : Loading problem definition '../templates/MaterialMacros.pro'<br>Info : Loading problem definition '../templates/Magnetostatics.pro'<br>Info : Selected Resolution 'MagSta_phi'<br>Info : Loading Geometric data 'magnet.msh'<br>Info : System 'A' : Real<br>P r e - P r o c e s s i n g . . .<br>Info : Treatment Formulation 'MagSta_phi'<br>Info : Generate ExtendedGroup '_CO_Entity_15' (NodesOf) <br>Info : [rank 8] System 1/1: 1658225 Dofs <br>Info : [rank 7] System 1/1: 1658225 Dofs<br>Info : [rank 3] System 1/1: 1658225 Dofs<br>Info : [rank 4] System 1/1: 1658225 Dofs<br>Info : [rank 1] System 1/1: 1658225 Dofs<br>Info : [rank 2] System 1/1: 1658225 Dofs<br>Info : [rank 10] System 1/1: 1658225 Dofs<br>Info : [rank 6] System 1/1: 1658225 Dofs<br>Info : [rank 5] System 1/1: 1658225 Dofs<br>Info : [rank 11] System 1/1: 1658225 Dofs<br>Info : [rank 0] System 1/1: 1658225 Dofs<br>Info : [rank 9] System 1/1: 1658225 Dofs<br>Info : (Wall = 30.3178s, CPU = 181.936s [14.804s,16.964s], Mem = 8228.93Mb [685.133Mb,689.43Mb])<br>E n d P r e - P r o c e s s i n g<br>P r o c e s s i n g . . .<br>Info : CreateDir[../templates/res/]<br>Info : Generate[A]<br>Info : Solve[A] <br>Info : N: 1658225 - preonly lu mumps<br>Info : SaveSolution[A]<br>Info : (Wall = 87.9995s, CPU = 489.904s [38.456s,48.752s], Mem = 14249.9Mb [1109.46Mb,1297.96Mb])<br>E n d P r o c e s s i n g<br>P o s t - P r o c e s s i n g . . .<br>Info : NameOfSystem not set in PostProcessing: selected 'A'<br>Info : Selected PostProcessing 'MagSta_phi'<br>Info : Selected Mesh 'magnet.msh'<br>Info : PostOperation 1/4 <br> > 'res/MagSta_phi_hc.pos'<br>Info : PostOperation 2/4 <br> > 'res/MagSta_phi_phi.pos'<br>Info : PostOperation 3/4 <br> > 'res/MagSta_phi_h.pos'<br>Info : PostOperation 4/4 <br> > 'res/MagSta_phi_b.pos'<br>Info : (Wall = 377.562s, CPU = 1118.17s [80.556s,207.128s], Mem = 14254.1Mb [1109.95Mb,1297.96Mb])<br>E n d P o s t - P r o c e s s i n g<br>Info : Stopped (Wed Aug 9 09:26:37 2017, Wall = 377.851s, CPU = 2012.12s [162.712s,207.26s], Mem = 14254.1Mb [1109.95Mb,1297.96Mb])<br><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>2) Single CPU run:<br data-mce-bogus="1"></div><div>******************<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>/home/quemener/local/OneLab_gq/GetDP/bin/getdp magnet -solve MagSta_phi -pos MagSta_phi<br>Info : Running '/home/quemener/local/OneLab_gq/GetDP/bin/getdp magnet -solve MagSta_phi -pos MagSta_phi' [GetDP 2.11.1, 1 node]<br>Info : Started (Wed Aug 9 09:27:06 2017, Wall = 0.146171s, CPU = 0.136s, Mem = 25.9609Mb)<br>Info : Increasing process stack size (8192 kB < 16 MB)<br>Info : Loading problem definition 'magnet.pro'<br>Info : Loading problem definition 'magnet_data.pro'<br>Info : Loading problem definition '../templates/MaterialDatabase.pro'<br>Info : Loading problem definition '../templates/MaterialMacros.pro'<br>Info : Loading problem definition '../templates/Magnetostatics.pro'<br>Info : Selected Resolution 'MagSta_phi'<br>Info : Loading Geometric data 'magnet.msh'<br>Info : System 'A' : Real<br>P r e - P r o c e s s i n g . . .<br>Info : Treatment Formulation 'MagSta_phi'<br>Info : Generate ExtendedGroup '_CO_Entity_15' (NodesOf) <br>Info : System 1/1: 1658225 Dofs <br>Info : (Wall = 10.7856s, CPU = 7.42s, Mem = 688.309Mb)<br>E n d P r e - P r o c e s s i n g<br>P r o c e s s i n g . . .<br>Info : CreateDir[../templates/res/]<br>Info : Generate[A]<br>Info : Solve[A] <br>Info : N: 1658225 - preonly lu mumps<br>Info : SaveSolution[A]<br>Info : (Wall = 40.7256s, CPU = 47.028s, Mem = 4496.32Mb)<br>E n d P r o c e s s i n g<br>P o s t - P r o c e s s i n g . . .<br>Info : NameOfSystem not set in PostProcessing: selected 'A'<br>Info : Selected PostProcessing 'MagSta_phi'<br>Info : Selected Mesh 'magnet.msh'<br>Info : PostOperation 1/4 <br> > 'res/MagSta_phi_hc.pos'<br>Info : PostOperation 2/4 <br> > 'res/MagSta_phi_phi.pos'<br>Info : PostOperation 3/4 <br> > 'res/MagSta_phi_h.pos'<br>Info : PostOperation 4/4 <br> > 'res/MagSta_phi_b.pos'<br>Info : (Wall = 324.758s, CPU = 132.924s, Mem = 4496.32Mb) <br>E n d P o s t - P r o c e s s i n g<br>Info : Stopped (Wed Aug 9 09:32:31 2017, Wall = 324.946s, CPU = 133.032s, Mem = 4496.32Mb)<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Does any one has clues to explain such a behaviour ?<br data-mce-bogus="1"></div><div><br></div><div data-marker="__SIG_PRE__"><div><div> <span style="color: #003366;"> Gilles <br></span></div><br></div><div><table style="width: 792px; table-layout: fixed; height: 145px;" cellpadding="0" border="0"><tbody><tr><td style="width: 200px; text-align: left;"></td><td><span style="color: #000080; font-size: 10pt;"></span><span style="color: #000080; font-size: 10pt;"></span></td></tr></tbody></table></div></div></div></body></html>