>> I run the test on a quad core machine with mpiexec -n 1, 2 and 4 to see >> the parallel scaling. The cpu times of the test are: >> >> Solver/Precond/Sub_Precond >> >> gmres/bjacobi/ilu >> >> -n 1, 1917.5730 sec, >> -n 2, 1699.9490 sec, efficiency = 56.40% >> -n 4, 1661.6810 sec, efficiency = 28.86% >> >> bicgstab/asm/ilu >> >> -n 1, 1800.8380 sec, >> -n 2, 1415.0170 sec, efficiency = 63.63% >> -n 4, 1119.3480 sec, efficiency = 40.22% > > These numbers are worthless without at least knowing iteration counts.
I cannot show the iteration counts as I run it 50 time steps, 10 maximum iterations for each time step, and 200 number of sweep (or maxit in KSPSetTolerance()) I test also our inhouse solver on the same machine, which is much slower than Petsc solver but scales better. -n 1, 10022.8360 sec, -n 2, 5684.1490 sec, efficiency = 88% -n 4, 4067.0480 sec, efficiency = 61.61% efficiency = 100*Speedup/nproc Speedup = (cpu's time of -n 1)/(cpu's time of nproc) If anyone has done parallel scaling test, it would be very kind, if you could share the test results. Regards, Jarunan
